Tuesday, 24 January 2012

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. 

Friday, 20 January 2012

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! =)

Monday, 16 January 2012

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).

Tuesday, 10 January 2012

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!