The involving aroma of seductive Oman

Walking in the charming markets of Oman is not only about what we see, it is much about the scents. Unlike most places I’ve visited in Europe and Asia, in Oman even the Market (Suq in Arabic) has a lovely aroma, leaving a comfortable warm feeling in the air. I could feel this scent everywhere – in the streets, markets, houses, clothes and it is about the best memories I have from this land. Therefore I still keep a wee wooden box filled with Omani frankincense in my room, and whenever I open this box the aroma makes me fly back to Arabia, so I do it several times. And I do also keep a little scented stone on my wallet, just because it’s nice.

Frankincense from Oman

Frankincense is very special and sacred since ancient times, and in the past it was equated to gold in the market. It was used as an offering to gods, and as a medicinal fumigant for diseases and against evil odors. Egyptians also believed that frankincense was the sweat of Gods. Frankincense is also mentioned several times in the Bible, and it has been used to make holy incense used for worship since the time of Moses. In Christianity it is very much known as one of the three gifts to baby Jesus, along with myrrh and gold, representing the divinity of Christ, as it was used as an offering to God.

All that made sense to me, and I do understand the status of divinity associated with this odoriferous resin – frankincense has a unique and magical aroma, leading you to a deep involvement with the place. And it is not to be surprised that it brings so many feelings as it comes from the plant’s own “blood”, carrying along all the purity of its nature. It is much as you have the whole soul of the desert transformed in the sense of smell.

Sap from wild Boswellia sacra. Photo by: Khalid Al Farsi

Frankincense stones are nothing but the dried sap (resin) of Boswellia sacra (Burseraceae), a shrubby tree native to Oman, Yemen and Somalia, growing also in Ethiopia.

Natural habitat of Boswellia sacra, in Omani lands. Photo by: Khalid Al Farsi

Burseraceae is a family belonging to Sapindales, having Anacardiaceae as a sister family. The flowers are small but gorgeous, organized in racemes. Floral structures are simple, not hard to recognize, and they seem to have what well-behaved Rosid is expected to have: five sepals, five petals, 10 stamens arranged in 2 rows of five, a superior ovary and a beautiful and wide nectary disc. The most characteristic structures here are the white broad petals, and the conspicuous fleshy nectaries.

Flowers of Boswellia sacra. Source: Flickr (Scott Zona)

Notice that the first row of stamens (closer to the petal row) is opposite the sepals, and the second row (closer to the gynoecium) is opposite the petals. Sorry for the low quality of the pictures.

I admit that today the story wasn’t much of a flower story, but I felt like introducing you this very special plant that brings along with it a high spiritual feeling. Unfortunately, it seems that the wild population of these trees is declining due to a lower regeneration caused by the early death of the youngs before flowering and thus, seeding. However, it seems that it is not considered to be threatened, according to the IUCN Red List, and we hope that it remains likewise and that the population of Boswellia can grow happy and healthy, inspiring us all with its warm and exotic sense from South Arabia.

The family from the skies

“Aster” is the greek name for “Star”, which is also the name of the type genus of one of the most diverse families of flowering plants: Asteraceae (also known in Botany under the old name of Compositae).

When I think of the name Asteraceae I cannot avoid thinking about the supreme star that lights and heats the planet we live in. In fact, I think the name Aster is well attributed due to morphological similarities that we might find between an Asteraceae flower and a star, or even the Sun itself. Stars usually have a core and irradiate light through rays of light. In Asteraceae inflorescences do also resemble stars by having the core flowers tightly grouped in the centre and the ray flowers on the edges.

The fact of having this extremely cosmopolitan and diverse family under the name of “Star”, makes me think that they can be found anywhere in the world as easily as finding stars in the dark sky above. So let’s explore a bit the secret recipe for the high success of this family which became the largest among core eudicots. They which are so widespread that can be found naturalized in all continents (except Antartica) and in most environments. Such success must be related with their floral morphology! And if it’s not directly related with the floral morphology it doesn’t matter because I will introduce it anyway.

The inflorescence type is an exclusive of the family, it is very odd and it comes in a pseudanthium-like inflorescence. I bet some of you are now wondering what the pseudanthium is, or scrolled down the window to check on the glossary. Botanists call pseudanthium to some types of inflorescences where flowers are organized in such a way forming a structure that looks like a single flower, even though it’s a group of flowers! We find these pseudanthia in all Asteraceae, and in this family the pseudanthia are special as they are organized in a disc. The botanical name Compositae was also based on the morphology of such inflorescences, which can also be called compound flowers, meaning a flower made out of many flowers, or opposite to single flower.

When it comes to Asteraceae, even some structures have special names as they don’t occur in other plant groups, starting with the inflorescence, the capitulum. Also the calyx usually differentiates into a pappus (a series of hairs or bristles) instead of the typical 5 sepals. Petals are always fused, forming a stamen-petal tube (disc flowers) or forming the monosymmetric corolla we find in peripherical flowers. Finally, the tubular flowers are bisexual but the peripherical ligulate flowers are usually pistillate (lacking male organs) or sterile.

Florets of an Asteraceae cappitulum

One of the most interesting characters of these flowers is known by the secondary pollination mechanism. This mechanism is simple and effective at the same time. The tube formed around the stigma on tubular flowers is the basis of this mechanism, as stamens are organized all very tight around the gynoecium, and when it pops outside the flower, it is covered with pollen on the outer (abaxial) side of the stigma. This mechanism is interestingly effective as it avoids self-pollination (as the pollen is attached to the abaxial side of the stigma and the fertile region is the inner or adaxial side, which only opens when it sticks totally out from the floral tube).

The pollen gets attached to the abaxial side of the stigma, the receptive part of the stigma is the adaxial side. Mature anthers in the left side and mature stigmas in the right side. The ovaries are always bicarpellate and inferior.

The beauty of simplicity

I have been trying for long time to talk about palm tree flowers. Palm trees have a great symbology in some religions, being considered as the tree of life in ancient Egypt, and in the Kabballah. In Judaism it has a symbolic importance as one of the four plants used during the Sukkot, according to the Torah. Also in the Quraan palm trees, especially date palm trees, are mentioned several times, and so a certain significance is given in the Islamic culture. In Christianity, palm leaves are used to celebrate the Palm Sunday, the Sunday before Easter, remembering Jesus’ triumphal entry in Jerusalem. It happens that in the region where all these monotheistic religions were founded, palm trees are probably the taller trees growing in the wild, so it does not surprise me that they are mentioned in the sacred books in many different occasions, giving them this mysticism.

Virgin Mary nurtured by a palm tree, as described in the Quran (Source: Wikipedia)

However, Arecaceae (the family of palm trees) is originally from tropical and sub-tropical regions, where they are much more diverse due to the typical wet and hot conditions. That is probably why palm trees are usually associated with our idea of paradisiacal islands, exotic beaches and holiday’s advertisements. Only in South-East Asia these trees started to gain a different meaning to me. They were part of the landscape everywhere, giving that tropical touch to the surrounding environment. I could find them in the beach, in the mountains, near the rivers, you name it! And even though I have never paid much attention to these plants because I never found them neither pretty nor very attractive, it seemed to me that I was starting to understand their beauty somehow. In Thailand I had the opportunity to look closely at the flowers like never before, and it was like finding a hidden treasure that nobody have ever heard about.

Male inflorescences and flowers of Pinanga sylvestris

Female tree, infructescences and fruits

The flowers are amazing, they are tiny and immaculate, strong and vivacious – a mix between delicacy and will to live. It was like the flowers were confident and ready for the adversities of the world! Yes, I kind of gave them “flowerality” (or the “personality” of the flower). However, I thought that the structure itself was a bit inglorious to talk about, in the sense that they are so simple that it won’t bring anything new, but I will introduce you the palm tree flower structures anyway! Like all monocots they are trimerous, having a bipartite perianth of 3 organs (3+3 tepals), and 2 whorls of 3 stamens. The carpels are also trimerous. The flowers can be both uni- or bi-sexual, depending on the species, but they are usually small and white, organized in panicles or spikes hanging from the tree top.

Bi-sexual flowers of palm tree

How did such a small and simple flower return such a feeling of amazement? Maybe there was nothing complex to show you here, but isn't simplicity the purest sense of beauty? Isn’t simplicity effective? There is no doubt about this! Keeping it simple seems to be the watchword in palm flowers, and that leads to a pollination syndrome which is still not very well defined in many groups only because it is not specific.

It is just simple, effective and beautiful.

The Apple of Sodom

It was another beautiful sunny day in Israel and I had decided to go outside Jerusalem to see the Dead Sea like all well behaved tourists do. Just before I get there, I have decided to walk around in that inspiring desert environment that surrounds the area, right close to Ein Gedi. After passing by a family of wild gazelles that made me company for few minutes, I stopped by a wonderful tall shrub. I was standing by a stunning member of Apocynaceae. The plant was Calotropis procera and their flowers, as usual, took the breath out of me! They were fleshy, big and colourful and the only thing I wished was to have someone with me so I could share all my thoughts about those flowers. But there was nobody passing by for as long as I stayed in the area, and the gazelles wouldn’t understand my excitement about their food, so I stay just admiring them for while. In such a harsh environment, the last thing I was expecting to find was such showy purple flowers – that shrub was just like an oasis of beauty in the desert.

On the left side: the gazelle happy family; on the right side: the shrub with the Dead Sea on the background

My astonishment was nothing but the proof of my infinite ignorance: these plants are actually quite common, especially the Dead Sea region. They are commonly called the “Apple of Sodom” because of the characters of the fruits, which are as big as apples and because of their dehiscence. The fruits are described as “exploding” or “dissolve into smoke and ashes” when you try to pluck them, possibly remembering the biblical scriptures of the destruction of Sodom and Gomorrah. This happens only because the fruits are hollow, but unfortunately didn’t have the opportunity to see them “dissolving” on my hands as the plants were not fruiting yet. The seeds produce silky strands which can be used as wicks for oil lamps, except in Jewish Shabbat lamps, according to the Mishna. These strands may also be used as natural textile fibers for other purposes. This biblical plant, as a member of Apocynaceae, produces a toxic milky sap, so be careful while handling it!

Fruits of Calotropis procera (Source: Flowersinisrael.com)

Unfortunately I didn’t dissect any flowers, so I don’t have good pictures to show morphological characters, but I will try to make it understandable. In Asclepioideae (old Asclepiadaceae family, today a sub-family of Apocynaceae) there is a structure called gynostegium. The gynostegium is the fusion between stamens and stigma and it is only known to be found in this family, however it resembles another structure appearing in a totally different family: Orchidaceae. The structure described in Orchidaceae is the gynostemium, and is also described as the reproductive structure of Aristolochiaceae. But the difference between a gynostegium and a gynostemium is not easy to detect, it is a matter of timing of fusion during the development of the flowers. While in Orchids and Aristolochiaceae the fusion between stamens and style is congenital, in Apocynaceae the same fusion is postgenital. But the problem now is to understand the difference between congenital and postgenital fusions.

Flower detail of Calotropis procera

These terms might be confusing to explain and understand, so to make it simple I would just say that the real fusion is the postgenital fusion, as we can identify it as a fusion. In postgenital fusion the organs develop independently until a certain point where they start fusing to each other by marginal adhesion. In congenital fusion you cannot see this for the simple reason that the organs are actually growing and developing together since the beginning.

It seems sometimes that botanists like to make up random names just to make other people, but terminology is a useful tool. In this case the names are so similar that they can without a doubt become a misunderstanding problem easily! The truth is that humans try to understand Nature the best they can by inventing names to communicate with other people, share knowledge and think together. But then we have to interpret the words we’ve created to try to understand plants – at the end it seems that botanists just like to play word-games. And it is much more fun to use words hard to pronounce.

Ranunculaceae and the origin of petals

There are events that change the course of evolution. In my opinion one of the most important events that have changed the course of evolution in flowering plants was the transition between spiral to cyclic flowers. This episode was obviously gradual as everything in Nature is, but it is still incredible to observe this transition in living plants and there is a group telling us this episode better then any other.

Early diverging eudicots from APG III tree

Early diverging eudicots is the transitional group between basal angiosperms and core eudicots. In fact, plants belonging to this group are inbetweeners, they share characters from both groups, bringing an extreme floral diversity to the plant world. They were the authors of many innovations, such as nectaries, zygomorphy, perianth differentiation in two different whorls (calyx and corolla) and many other novelties. One of the best examples of this diversity is Ranunculaceae, and today I have brought one of the most stunning creations of this family in the form of Aquilegia. In fact, most members of Ranunculaceae have incredible structures where you can almost interpret the gradual formation of cyclic flowers, many of them with extravagant nectaries acting also as petals. Aquilegia is just another example, and the flowers are pretty much incredible!

Side view (left) and front view (right) of Aquilegia flower

In Aquilegia, pentamery is already established, and we can easily find the bipartite perianth with 5 sepals and 5 petals. The petals, however have a very particular character – they are spurred, producing nectar to attract pollinators. This is the reason why many authors prefer using the term “nectar leaves” instead of “petals” in Ranunculaceae.

Left: View of the back of Aquilegia flower; Right: Detail of Nectar leaf of Aquilegia

These nectar leaves are of extreme importance on the evolution of a bipartite perianth, and in Ranunculaceae this transitional situation is still visible. They are not true petals yet, but structurally that’s how we interpret these structures. The tepals, structurally acting as sepals in this Aquilegia are the true perianth members of the flower. The nectar leaves are nothing more than stamens that lost their original reproductive function, becoming staminodes (or sterile stamens) and latter gaining a new function to attract pollinators. This is how true petals were born, they are nothing but modified staminodes that evolved in the direction of pollinator attraction. On the other hand, sepals evolved directly from tepals (leaves) gaining the function of organ protection (the reproductive organs – stamens and carpels).

Origin of petals in Aquilegia. The outer whorl of stamens loosing the reproductive function, and gaining later the function of pollinator attraction, becoming showy  and colourful (like petals) and producing nectar. Tepals at the same time gain the function of flower protection, like sepals.

However, some researchers believe that the origin of petals is not entirely the same for all members of Ranunculaceae. Some members of the family might indeed have their bipartite perianth as a result of the ascension of the bracts to the base of the receptacle, originating the sepals. Likewise, the true perianth (the tepals) gave origin to the petals. Ranunculaceae seems to be a family of flower structure experiments, trying which structure is the best to have. In any case, it seems that after this group pentamery and bipartite perianth were successfully achieved characters, well established in the rest of Eudicots.

The Portuguese Oak

I have decided to honor Portugal with this week’s post for two reasons: to celebrate the National Day of Portugal (which was last Sunday , the 10^th of June), but also to support the Portuguese team at the UEFA Euro 2012. So I have decided to bring you today the Portuguese national plant – Quercus suber, the cork oak.

Quercus is a monoecious anemophilous plant, meaning that the sexual organs are separated in different flowers and are wind-pollinated. Thus the flowers are simple, small and shy, with a rather simple structure, but I thought this is a good opportunity to introduce you the wonders of wind-pollination. Anemophilous plants (wind-pollinated) are mainly found in two orders: Fagales and Poales and this, first of all, give us some clues about the environment shared among wind-pollinated plants. They are either trees (Fagales) or grasses (Poales), possibly due to the fact that flowers bloom high in the canopy, where the pollen is easily reached by the wind, but not as much by small insects. Another reason is possibly the windy and dry conditions found in steppes or desert-like environments where grasses reign. In such environments, the wind is a common and available resource much prevalent and reliable than insects. Possibly, also due to the winds typical of such environments insects are here less abundant comparing with, for example, forest-like environments. For this reason, plants found here have started to invest their energy in other characters, allowing a more efficient pollination and thus the flowers became adapted to wind pollination.

To make it easier for you to understand the main differences between anemophilous and entomophilous (insect-pollinated) plants, I have made this table to share with you:

Comparision between Anemophilous and Entomophilous floral characters

Because anemophilous plants have no need to attract anything, there is no need to invest energy producing big showy flowers, or expensive precious nectar. Instead, these plants produce many small flowers and large quantities of light pollen, which can be easily carried away by the wind. To facilitate the wind to take the pollen away, the petals are much reduced, and sometimes they are completely missing. Likewise, the stamens are hanging outside the flowers, waiting for the breeze.

Male inflorescence of  Quercus suber with the stamens hanging outside the flowers
(Source: www.flora-on.pt)

Also the typical inflorescences found in Fagales are definitely adapted to this pollination syndrome. Catkins of small and light flowers are easily moved and shacked even by a light breeze, and this allows the pollen to be released and spread easily. Because the pollination isn’t specialized like in entomophilous plants, the stigmas also have to be adapted to the wind pollination, so the surface of pollen reception is much bigger. This can be very easily observed in Poales, where the stigmas are long and feather-like, increasing the surface for an effective pollen reception.

Feather-like stigmas typical of grasses. Left: Arrhenatherum album; Right: Ammophila arenaria (Source: www.flora-on.pt)

Also, the position of the inflorescences in the tree isn’t random – male flowers are found in the lower older twigs and female flowers in the upper younger twigs. This is to avoid self-pollination (it is more unlikely that the pollen from below flies up and fertilizes the female flowers, but if female flowers were below, any pollen grain falling from the catkins above could fertilize them).

Flowers and inflorescences of Quercus suber

Wind-pollinated flowers are so shy that they can be unnoticed many times, especially by non-botanists. The truth is that they are not hiding, they are right there and it is fascinating to observe all the structures that seem to be undercover by the green foliage. Finding them is like finding a precious treasure, which is visible for everyone, but unnoticed by most people. That is the reason why every time I show wind-pollinated flowers to non-botanists they become astonished and quite surprised... These flowers might not be the prettiest, but they are pretty cool too.

The Passion flower

What is the first think you think of when someone mentions passion? Perhaps romantic love? Physical or sexual attraction for someone, or maybe just sex? Do you think of the same meaning of passion when the subject is the passion vine? What is the origin of this plant’s name? Is the passion fruit an exotic aphrodisiac? Well, not exactly but maybe if you’re in the right mood anything can work as an aphrodisiac...

Passiflora (Passifloraceae), the genus of the passion vine, gained this name due to the great imagination and devotion of the Portuguese and Spanish Jesuits which associated most morphological characters of the plant to symbols of the Passion of Christ. While exploring the exotic tropical rainforests of South-America they were astonished not only by the beauty and diversity of the plant (Northern-Central Brazil is an important hotspot of diversity for these plants) but also with all the symbolism that they immediately attributed to the plant. For the Jesuits, the flower of the passion vine had all the symbols of the Passion of Christ, and so it was named after this passion, not any other romantic or sensual passion that people might probably think of – after all it is indeed an exotic and extremely sweet fruit.

Flower diversity in Passiflora sp.

So now you are curious about the symbols, and the Jesuits were indeed very attentive – they looked at all the flower organs finding explanations for numbers and shapes of most of them. Let’s see…

The flower is pentamerous, with 5 sepals and 5 petals, representing the 10 faithful apostles (excluding Peter, the denier and Judas, the betrayer); the corona represents the crown of thorns with which roman soldiers crowned him as the “King of the Jews”; the ovary, a chalice shaped structure, represents the Holy Grail; the 3 stigmas represent the 3 nails used in Christ’s crucifixion and the 5 anthers the 5 wounds (1 in each hand and foot and the last one in his chest caused by the Holy Lance). But not only the floral structures were considered to be the symbols of the Passion of Christ. The characteristic leaves with pointed tips resemble the Holy Lance that confirmed Christ’s death and the tendrils represent the whips during the flagellation. The colours have also been attributed a meaning, since many species are white and blue colors, representing heaven and purity, and we must not forget the purple, which was also the colour of the robe that romans covered Jesus after crowning him.

The association between the flower and symbols of the Passion of Christ

Apart of all the symbolism involving the plant, there are also interesting characters related with the ecology of the plant that I would like to share with you. Every single part of it is edible, meaning that this plant is the herbivore heaven! They can eat the leaves, tendrils, flowers and there is plenty of nectar in the floral and extra-floral nectaries. To avoid getting eaten by all the herbivores, Passiflora seem to have made a deal with the ants by feeding them with nectar from extra-floral nectaries (usually present in bracts but also in leaves). Likewise, the ants protect their plant from herbivores and nectar robbers. Also the ants allow true pollinators to access the floral nectaries, allowing the successful reproduction of the plant. It sounds beautiful, but it is not as simple as it might sound – it relates many ant species, so a lot of different behaviours with different Passiflora species and environments. In any case, Passiflora and ants seem to get along very well and it seems to be a fair symbiotic relationship.

Ants feeding on nectar from extra-floral nectaries of the bracts of Passiflora

After attributing so many symbols to this plant, I wonder what Jesuits thought noticing so many ants around the vines getting rid of the hungry predators, protecting their “holy” source in exchange of precious nectar. I will let you meditate on this, wishing you a blessed Thursday of Corpus Christi.

Long wait, but with new stories to come!

Dear readers,

I am very happy to announce that I am finally back home, and so are the tales! I have been traveling since my last publication, and I found out later the impossibility of traveling and getting organized with good stories and pictures to publish. But I am back now and there is a lot to share! During these trips I have been to many different environments and seen a lot of beautiful flowers.

Each flower has a story to tell – the story of their past, and I try to translate them to you. But also because plants have a deep presence in human cultures, people have interpreted plants and flowers in different ways, giving them meanings and telling other stories which I found amazing and would be pleased to share with you!

A new story is ready to be published tomorrow – don’t miss it! J

Myrtaceae and the Bombacaceous-Malvaceae

“Someone brought this for you today”, he said smiling. It was a flower and it had a smell of challenge too. It was a big white flower with many long stamens, fused in the base in groups. The style was sticking out from the middle of the stamens tube and it also has a profound cup-shaped hypanthim and 5 long white petals. “Humm, stamens fused at the base with the style like this is a very Malvaceae-like character… But the most obvious character of this flower is definitely the large number of long stamens with only one style coming from the middle”, I thought innocently, “Humm, plus this hypanthium, it looks very Myrtaceous”.

Myrtaceae?! Tremendous fail!

After a while I found out I was looking at a Bombax anceps flower, a common tree here in northern Thailand, belonging to the old Bombacaceae (now Malvaceae – yes, Malvaceae!). The tree is easily identifiable because of the thorns found in the bark, and at this time of the year also because of the big and showy white flowers and no leaves (it is a deciduous tree).

Young Bombax anceps bark and flowers - It actually looks quite Myrtaceous from a distance

These flowers produce an amazing smell due to the large amounts of nectar secreted in the morning, attracting many birds for the pollination daily-service.

Evidence of pollinators having nectar of Bombax ceiba for breakfast

Everyday I see this small beautiful tree, but it only started flowering a few days ago, and let me tell you it is a must-see not only for flower-freaks (like me) but for everyone – every time I pass by the tree with someone else I hear their “Wow’s”… No wonder!

But why was I so confused between these two families, Myrtaceae and Malvaceae? There should be nothing to be confused about; in fact they do belong to their own orders, Myrtales and Malvales, meaning that they are quite different. But they do have similarities also: both Malvales and Myrtales belong to the Rosids (actually to the same branch in the Rosids – the Malvids), and that might explain morphological misunderstandings.

Malvaceae flowers are characterized for having a synandrium, a structure where all the stamens are fused together with the style coming from the middle of the synandrium. Another good character is the contorted corolla fused basally with the androecium. The number of stamens is very much variable, ranging from 5 to many, however when many they are grouped in 5 or 10 groups, depending on the number of whorls (one in Bombax anceps and two in Bombax ceiba).

You can probably summarize a Myrtaceae-like flower with 3 main characters: large hypanthium, a lot of long (showy) stamens and reduced petals. In Myrtaceae the hypanthium is very much developed, having a high number of stamens placed at the top (the ring of stamens). Bombax anceps flowers reminded me of Myrtaceae flowers because I totally ignored one of these characters: the petals! But also the stamens are different – in Myrtaceae they are not fused together, not in groups or in synandria, so why did I think about Myrtaceae when I looked at the flower? Because of the calyx shape in Bombax anceps flower, which resembles a hypanthium.

Find the differences (the B. anceps flower didn’t have style anymore when I took the picture, but it was long and red as you can probably see in the first picture of this post)

The hypanthium is a structure sometimes hard to identify and define, and originating many times misunderstandings on the interpretation of the morphology of the flower. This means that it is an important structure to help us to find the big group (Rosids), but we cannot ignore the other structures. 

The Tết’s flower

Have you been looking at the moon? It’s getting smaller and smaller and smaller…The New Moon is coming very soon, and so is the Lunar New Year! To celebrate this very special date, I will dedicate a post to a very special flower used in the Vietnamese (and maybe in other nations?) traditional celebrations of the Lunar New Year, or “Tết”. The first time I saw these flowers was here in Thailand and they kept my attention because of weirdness of their looks...

What else can I say? It looks just weird to me!

Since the first time I saw this flower I wondered to which family it belongs to, but the morphological clues didn’t ring me any bell - at all! I had no idea about the family of this plant. Until one day, when my Vietnamese herpetologist friend suggested me to talk about one of the most famous plants in Vietnam – Ochna integerrima. I was very much surprised when I realized that it was the flower I was wondering about for so many weeks! Thank you in advance for this, Ha. 

Ochna belongs to its own family, Ochnaceae and no wonder I could not identify this family – I have to admit I knew very little about Ochnaceae until now! But now I can say that I know little enough to dedicate one entire post to these flowers. Ochna integerrima is the most celebrated plant in Vietnam, because it blooms during the Tết, having a special meaning for Vietnamese culture. The Vietnamese believe that these bright yellow flowers bring luck and prosperity for the coming year.

Source: http://www.freephotos.biz

Another curiosity about this plant came up while I was googling “Ochna integerrima”, coming up automatically “Vietnamese Mickey Mouse Plant”… This common name made sense to me as I had seen the plant already, but for those who have never seen or heard about it before it might sound strange. This plant produces some beautiful round-shaped black berries on a bright-red head-like receptacle. So probably, some cartoon-lover botanist saw Mickey Mouse’s ears on the berries and decided to name it this way!

Fair enough!

After what happened I had to search about this family and will give you now some tips so we can all easily identify Ochnaceae. No more excuses! The flowers are usually pentamerous, having 5 sepals (usually enlarging in fructification) and 5 free petals (often caducous). The number of carpels is variable, sometimes fused having a terminal style, or if free with a gynobasic style.

Unfortunately, I didn’t find any flower with the petals as they are caducous and I only found later stages, already forming fruit

So now that we all know how an Ochnaceae flower looks like, I would like to wish you happy celebrations for those who celebrate. For those who do not usually celebrate, I suggest you to spend some time looking at the sky for a change, trying to find the New Moon!

Happy Lunar New Year everyone! =)

Well-behaved plants live in wild Borneo

Probably the most interesting group of plants for the majority of people are the carnivorous plants because of their behaviour with insects. Wait, because of the insects’ behaviour with these plants! Well, in any case we must all agree that carnivorous plants were a wild invention of Nature. 

Different growth stages of pitchers in the QBG carnivorous plants glasshouse

My opinion about them became even wilder when I found an old article about a Bornean pitcher plant (Nepenthes bicalcarata), which relationship with insects is absolutely unexpected for a carnivorous plant. So first, let me remind you some aspects about the biology of these plants: pitcher plants are known by getting nutrients from insects as a supplement. Their strategy is to attract insects using a trap, a modified leaf (the pitcher), which is full of enzymes and digestive liquid where the nutrients can be absorbed. 

In Nepenthaceae, the leaves are differentiated into pitchers and the petioles are the photosynthetic part of the plant, having the function of the leaf but not being a true leaf

The insects are attracted by the extra-floral nectaries and often fell in, drowning in the fluid. However this particular species, Nepenthes bicalcarata, nests ants (Camponotus schmitzi) in their swollen and hollow tendrils. Strangely, these ants forage on the inner side of the pitcher, crawling over the slippery walls without difficulty and even swimming in the pitcher fluid to forage and feed on the insect prey’s of pitchers. So, what is the advantage for the plant on having other insects eating the food that they get alone by using their own pitchers? The ants only collect large prey insects – all the other small insects are digested and absorbed by the plant. Big preys take long time to digest, and this would end up on putrefaction and rotten pitchers, which is obviously something not very healthy for a pitcher plant to have. So these pitcher plants get rid of the large preys by offering them to their friends - ants. “Wow!” – I can hear you guys whisper. No worries, I whispered the same – these plants are really something!

Picture of Nepenthes calcarata sourced from the magical internet. It is possible to see the nests that the plant produces in the tendrils, as well as the "horns" that are very characteristic of this species

Even though this is all undoubtedly very interesting, the flowers of Nepenthes do also tell a story. Nepenthaceae, as all the members of Caryophyllales order have no petals, so their perianth has only one single whorl made out of sepals. The flowers are also easily recognizable by being dioecious (meaning that sexes are separated in different flowers, male and female) and tetramerous. Of course that a carnivorous plant also needs insects for pollination, so they do produce a lot of nectar to attract a lot of insects. Some will end up in the pitcher-insect-hell, but others will end up licking the sepals which are fully loaded with sweet nectar. It’s a matter of luck for insects I suppose.

Typical inflorescence of Nepenthes, a racemose with paired tetramerous flowers, each one subtended by one bract

Another very interesting fact about the Nepenthes are the male flowers, which have all the stamens (ranging usually from 4 to 24 in number) fused together in a structure which botanists decided to call “synandrium” (syn meaning fused and andrium referring to the male part).

Roses, my Lord

Once upon a time, in a kingdom of its name Portugal, there was a Queen known by her kindness and good heart. Queen Isabel of Portugal was devoted to the poor and sick. Her generosity was very popular but her husband, a very good ruler, considered charity to be of high cost to the kingdom and forbid her to do so. One day the King – El-Rei D. Dinis, found the Queen in one of her charity actions, giving money and bread to the poor. Afraid of the King’s punishment, Queen Isabel hid the bread in her lap, and the King asked: “Where are you going?”, she said: “I’m going to the monastery to decorate the altars”. Distrustful, the King asks to see what she is bringing in her lap, she replies saying “Roses, my lord”. Not happy with this answer, the King charges the Queen of lying as it was impossible to have roses in January. Therefore, he forced her to open the mantle to show what she was hiding. When she opened the mantle, the most beautiful roses fell from her lap – the hidden bread was turned into roses. The King was speechless and apologized his Queen. The story ran the whole kingdom and Queen Isabel of Portugal was proclaimed Saint by her people, and officially by the Pope 3 centuries later, in 1614. 

El-rei D. Dinis and his Queen, Isabel of Portugal

This legend is still very popular in Portugal and Queen Isabel is still much loved by the Portuguese after all these centuries, so I decided to share this with you. Of course this story is not coming alone without some hard-core botanizing, so make yourselves comfortable and get ready for what really matters!

I must admit that roses are not my type of flower – at least the ornamental roses; but they are an important group for the flower evolution point of view and that is enough to make me want to talk about it!

When talking about roses, maybe most people think about love, romantic stuff, Valentine’s day, maybe gardening or perfumes, but I have to be honest – the first thing crossing my mind is hypanthium. Not very romantic at all, right? But yeah, what is the real meaning of that weeeird word? And why do I think about hypanthia when thinking about roses? 

Roses from QSBG Rose Garden, Thailand

Roses gave the name of one of the most important groups of plants: the Rosids, one of the most successful groups of Angiosperms, representing around 25% of all angiosperm species - that is a big group! Certainly with so many species represented it is not easy to group all characters together, but there is one character that is frequently found and also a key morphological character. That is the hypanthium. The hypanthium is a cup-shaped structure (sometimes tubular) that elevates some floral organs. 

It is basically an elongation of the receptacle of the flower, and this lead to a lot of discussion in terms of the morphology of the flower as well as the naming of floral structures. With the elongation of the receptacle, sepals, petals and stamens are lifted up, and this causes confusion, “Is this a superior or inferior ovary?” Well, usually is neither both – it’s a half-inferior ovary!!

Ovary position related with the origin of the hypanthium

The evolution of this structure is thought to be on the origin of the inferior ovaries, a character found in more derived groups, useful as an extra protection to what really matters – the future babies. So basically the hypanthium is the evolutionary link between inferior and superior ovaries. Cool, uh?

New year, new stories

Dear all, I am back!

I hope you had a great Christmas and that 2011 ended the best way possible. I wish you all the best for 2012 and that you can make all your wishes to come true. I also hope you are you ready for more interesting stories as I am ready to tell more! But before that I will reveal the enigma that I posted before I leave.

The husbands are the stamens and the wives are the carpels. They share the same house, meaning that stamens and carpels are found in the same flower. The child is the seed formed and the rooms downstairs are the number of inferior ovaries. The husbands hugging the wives represent the stamen-petal tube. Mistresses living alone means that there are female flowers (without stamens). The city center here means a lot of houses, a lot of flowers, so the flowers are grouped in crowded inflorecences with both sexes in the center and female flowers in the periphery. So we have crowded inflorescences with central flowers with 5 stamens forming stamen-petal tubes, two carpels, two inferior ovaries and only on seed formed.

Any guess? This is Asteraceae, the family of sunflowers and daisies! Congratulations for those who found out! =)

Please be alert – new stories will be published very soon!

A wee enigma as Christmas present

Dear readers, 

As I will be traveling for the next weeks I won’t be able to post any story, so I decided to challenge you with a little charade… Maybe easy for some of you, hard for others, but you should give it a try!
I wish you all a Christmas full of love and all my best wishes for the New Year!

Now, L’énigme :


In this crowded flower city…

…Marriages are of five husbands with two wives. Husbands and wives live together in the same house, sharing the room upstairs; they are only allowed to have one child, sleeping in a single room downstairs, next to an unoccupied room. Husbands hug together surrounding their wives.
Mistresses don’t get married; they live in big houses with open view, outside the crowded city center. Mistresses always share a double room with another woman.



Will be waiting for your guess

See you in 2012! =)

Sacred-lotus? HELP!

How could I live in South-East Asia without mentioning anything about Lotus?

The Lotus flower is one of the most popular flowers in South-East Asia, it is the national plant of India and Vietnam, and is also deeply related with the Thai culture – it is present in art, traditions, food but most important of all, in their religion. These flowers have a great symbolic value for the Buddhists as it is present in Buddha’s life in many episodes. The first episode is even before his birth, when Queen Maha Maya had a dream of a white elephant holding a white a lotus flower in its trunk and walked around her three times. This dream was the prophecy of the birth of Buddha. Another famous episode tells that when Buddha was born he did seven steps and at each step a lotus flower appeared on the ground. Also Buddha is many times represented sitting on a lotus blossom while reaching the enlightenment as lotus blossoms symbolize full enlightenment.

Lotuses have a handful of meanings in Buddhism and the different meanings depend on the colour of the flowers (white, red, blue, pink, purple and gold) but also on the developmental stage (closed lotus, growing lotus and blooming lotus). Among the many different meanings, lotuses usually come associated with purity and divine birth, especially the white lotus.

I could dedicate an entire post explaining the importance and the different meanings of sacred-lotuses in both Buddhism and Hinduism, but that is not my aim. Lotuses have their own story to tell…

For many years the true taxonomical identity of lotus was hidden, I mean they are not what they appeared to be and their looks fooled botanists for long time. Only on late 80’s – early 90’s with the new molecular techniques botanists found out the scandalous truth: lotuses are not related to water lilies! Water lilies belong to the Nymphaeaceae (Nymphaeales order), a basal angiosperm family; lotuses belong to the Nelumbonaceae (Proteales order) which is not only a different family, but also placed in a much derived group. In conclusion: lotuses (Nelumbo) are today considered to be more closely related with sycamores (Platanus) rather than water-lilies (Nymphaea), as they are placed in the same order (Proteales).

It is not surprising that experts were deceived by the lotuses morphology. Characters as massive flowers, indefinite number of petals in a spiral position and ascidiate carpels are usually associated with basal angiosperms. This added with the adaptations to the aquatic environment shared by both groups made botanists conclude that they were very closely related. Not the case at all! All these similarities were not evidence of a shared evolutionary history, but of a convergent evolution.

Nelumbo or Sacred-lotus (left) vs. Nymphaea or Water-lilly (right)

 But there is no need to despair – after this post there are no more reasons to mistake a lotus flower with a water-lily. The most conspicuous difference between these two is the carpel, which in Nelumbo is an expanded receptacle that contains the seeds when mature. There are also marked differences in the stamens, which are laminar, or in other words leaf-like in Nymphaea (another common character of basal angiosperms). In Nelumbo the stamens form a ring at the base and are filamentous. Finally, it should also be mentioned that even though they are both aquatic, Nymphaea always has floating leaves and in Nelumbo they are above the water, as well as the flowers.

Different floral stages of Nelumbo nucifera (Sacred-lotus)

 But although the taxonomy is solved, the confusion is still reigning amongst common mortals and water-lilies are still called lotuses by many people (including Buddhists). So let’s see Nelumbo nucifera is the well known “sacred-lotus” and has pink petals, however in Buddhism the different colours of the lotus are associated with different meanings. The other two species of lotus (N. lutea and N. pentapetala) are endemic to the American continent, so they can’t be related with Buddhist traditions. This means that the only lotus that can be associated with Buddhism is pink! So where do the other colours come from? Nymphaea of course! The number of species of Nymphaea is much superior and the colours of the flowers are also very variable.

Colour diversity in Nymphaea

 Confused? Yeap me too, so I will leave you with this: Are the different colours associated with water-lilies instead of the sacred-lotus? Or are the colours symbolic variations of the sacred-lotus?

Hopping that some of you have a clue that helps to clarify this!

A Mid-Night Horror Story

Imagine you’re walking around in the forest at night and suddenly you find a pile of thin bones, you look up and you see a tree with dangling sickles and bats flying over… Creepy, uh? Well, maybe if you look a little bit closer the bones are not real bones, they are fallen branches and there are no sickles, they are just the fruits of this bat-pollinated tree – but that was scary enough! Today’s story is about the “Midnight Horror”!

The midnight horror tree, Oroxylum indicum, is a very popular tree in Southeast Asia due to their weird appearance, but despite of this, there is no reason to fear it - in fact most of the plant is used for medicinal purposes (leaves, seeds, bark and roots).

Oroxylum indicum. On the left side: the tree with hanging fruits; on the right side: the flowers.

Oroxylum indicum belongs to the Bignoniaceae family, a family with tropical distribution, belonging to the problematic Lamiales order. Lamiales encomprises some closely related and big families such as Lamiaceae, Acanthaceae, Oleaceae, Gesneriaceae, Scrophulariaceae, Plantaginaceae, Verbenaceae… The relationships between these families are not well understood and in many cases the morphological characters are not strong enough to determine the families’ delimitation, especially floral morphology. The typical Lamiales flowers have a well developed and basally fused calyx, a monosymmetric bilabiate corolla (upper and lower lips) and a superior bicarpellate ovary.

*Wow, botanists’ sophisticated dialect alert!*

Ok, ok… It is easier if I show some pictures, but what I want to show you here are the fluctuations on the number of stamens.

Typical Lamiales flowers. On the left: Lamiaceae, upper lip formed by 2 fused petals and lower lip formed by 3 fused petals; Dashed line representing the monosymmetric corolla. On the right side: Orobanchaceae, upper and lower lips fused forming the corolla tube; the calyx is fused on the base. 

In Lamiales the androecium varies from one to five stamens, including reductions of stamens into staminodes (sterile stamens) which are not well understood. This character is highly variable, and in my opinion is due to the current evolution of the group. This means that the characters for families’ circumscription are not well established yet, giving this morphological fluctuation as a consequence.

However, Bignoniaceae, has some characters restricted to the family, which makes it easy to spot in the field. The flowers in this family are very big, colourful and showy – hard not to see. They usually also have big nectarines in the base of the flower, releasing a strong and sweet fragrance – no wonder they are pollinated by big animals such as bats! Usually they have 4 fertile stamens and 1 unfertile stamen (staminode), but this species in particular has 5 fertile stamens and no staminodes. I have also found Bignoniaceae flowers with more variation, but as I explained before, I believe the presence or absence of staminodes is possibly related with a transitional evolutionary state. The stigma (the female part which receives the pollen) is usually wet and relatively broad.

Typical Bignoniaceae flower with 2 pairs of stamens (long and short) and one staminode

 The essential vegetative character of the Lamiales is the simple-opposite leaves, but luckily Bignoniaceae has compound opposite leaves, and this makes our lives easier! Bignoniaceae are usually represented by trees, shrubs and are also well represented in tropical America by climbers, having the terminal leaflet differentiated into a tendril.

So don’t forget, whenever you see a tree or climber with big showy flowers with the petals fused into a tube, check for the leaves, if they are compound, you probably found a Bignoniaceae! In the case of the midnight horror tree, they have big white or whitish flowers, blooming and releasing a sweet scent at night – all perfect characters for efficient bat pollination.