Saturday, 28 July 2012

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.

Sunday, 22 July 2012

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.

Thursday, 12 July 2012

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.