Wednesday, 19 December 2012

Garcinia mangostana - Manggis 山竹

Garcinia mangostana L.  is known as manggis in its region of origin – the Malay archipelago.  At other part of the world, it is colloquially known as mangosteen.    The local Malays crowned it as the “Queen of Fruits”, side by side with Durian as the “King of Fruits”.

Manggis is a tropical evergreen tree from the family Clusiaceae, formerly known as Guttiferae, which also include about 37 genera.  The genus Garcinia has at least another 50 species.

Young manggis fruits are white in colour.  As the fruits mature, they turn into green and finally dark purple when ripened.  By then, the fruits have grown up to 8cm in diameter, capped by a prominent green calyx, with a flat remnants of the stigma in a rosette at the bottom.  The rosette are supposedly correspond to the number of the aril sections.  The skin ( exocarp ) is hard, but easily squeeze-open.  The rind is about 10cm thick, spongy and reddish in colour. 

Edible arils are white, 4 – 8 segments, wedge-shaped, soft, sourly to sweet, mildly aromatic and fleshy.  Most seeds are infertile, with only 2 or 3 fully developed recalcitrant seeds.  The seeds must be kept moist to remain viable until germination.  It is interesting to know that the seeds are nucellar in origin, and not of the result of fertilization.

Tuesday, 18 December 2012

Hibiscus sabdariffa - Roselle 洛神花

Roselle, is Hibiscus sabdariffa L., a species of annual flowering plant native to the tropics of Old World.  Some says its from Africa, others say its from India...  Something for sure, it has been long cultivated in both Africa and Asia. 

Roselle is called by many names in different parts of the world, among the prominent ones are : flor de Jamaica, sorrel, bissap, asam paya, 洛神花 ,etc.  

The generic name is derived from the Greek word  βίσκος ( hibískos ), which was the name Pedanius Dioscorides (ca. 40–90) gave to Althaea officinalis.

Besides being called Hibiscus sabdariffa, roselle too have other synonyms : Abelmoschus cruentus Bertol., H. cordofanus Turcz., H. digitatus Cav., H. fraternus L., H. inermis, H. palmatilobus Baill., Sabdariffa rubra Kostel., etc

Roselle can grow up to 3 m in height. 
Leaves green to red ; alternate ; glabrous ; long-petiolate ; palmately divided into 3 – 7 lobes ; serrate margins.
Flowers large ; pink with dark-red center.
Fruits ovoid capsules, encapsulated by fleshy red calyx.

Roselle is a hermaphroditic, pollinated by insects.
It is a short-day plant, flowering when day-length is less than 13.5 hour.
Propagation is by seeds
Several cultivars are known : ‘Arab’, ‘Archer’, ‘Rico’, ‘Victor’, ‘Terengganu’, ’UMKL-1’,  etc

Roselle had been used in traditional medicine as a diuretic, laxative, and treatment for cardiac and verve disease.
Calyces are used as food colorings, infused into drink, made into jams, etc.
Young leaves are consumed as greens.  Heated leaves are applied to cracks in feet.  Mashed leaves are used to treat wounds and sores.

Roselle is rich in anthocyanins and protocatechuic acid.  Small amounts of myrtiline, chrysanthenin and delphinidin are also present.
Dried calyces contains gossypetin, hibiscetine and sadaretine.
Seeds contant g-tocopherol.

Saturday, 1 December 2012

Nymphaeaceae vs Nelumbonaceae

taxonomic position
angiosperms | Nymphaeales
angiosperms | eudicots | Proteales
Genera (species)
Barclaya (4), Euryale (1), Nuphar (11), Nympahea (33), Ondinea (1), Victoria (3)
Nelumbo (2)
temperate, tropical

botanical description
Root rhizome, sometime tuberous, latex, scattered vascular bundles.
Root rhizome stolonous with air chambers.
Leaves ovate, peltate, margin entire to spinose-dentate; floating, up to 300cmÆ,  submersed or emersed.
Leaves circular, peltate, slightly haired, margin entire, up to 60cm Æ, above water. 
Flower solitary, radial, bisexual, protogynous, diurnal or nocturnal, submersed or above water, termoregulated, entomophily, up to 40cmÆ; pistil 1, 3-35 carpellate.

Flowers solitary, radial, bisexual, protogynous, diurnal, fragrant, above water, termoregulated, entomophily, up to 25cmÆ; pistils numerous, 1-carpellate, large carpellary receptacle.
Fruit berry, nut or capsule; dehiscent or indehiscent..
Fruit conical pod, spongy, indehiscent, seeds in cavities.
Seeds numerous; aril present or absent; endosperm sparse; perisperm abundant; cotyledons 2, fleshy.
Seeds without aril, endosperm and perisperm; cotyledons 2, fleshy.
Pollen monoaperturate

Pollen triaperturate