Monday, December 24, 2007

Portulaca - Identification Help?!

This is tiny plant. Flower is about 2 cm across. Unlike other P. grandiflora type or hybrids where the flowers open early in morning, this flower open after noon. It appears to have been introduced into Singapore market from Taiwan.

Sunday, December 23, 2007

Iridescent Begonia

A cover photo got to be good right? Here it goes, Begonia pavonina. An iridescent begonia endemic to the highlands of West Malaysia. Iridescence is caused by refraction of light and it is probably best represented in cultivation by "blue" ferns - Pyrrosia sp or fern-allies - Selaginella sp.
Okay it is not really as exciting, the flash from my camera just manages to get it from the right angle and the former picture captures the full glory. The above picture captures an average plant. To some extend, the amount of iridescence depends on intensity of light on the plant, age of leaves, genetics ...

Saturday, December 15, 2007

Yellow Impatiens

This is probably the most beautiful impatiens species endemic to West Malaysia. I. oncidioides is a well documented species found along riverine forest in the montane zone of the Main Range. It is a lush herb that grows not too far from flowing water along earth banks in dappled shade.
Raymond Morgan mentions in his book Impatiens (Timberpress, 2007), that hybridizers have tried to cross this species with New Guinean species to produce good solid yellow flowers... but their efforts are not rewarded. The yellow genes appear to be recessive.

This species is not threaten on account of numerous seedlings and young plants. It even survived grass cutting activity along the trail. But it will not survive destruction of habitat unless transplanted to a suitable montane riverine valley. M. Henderson described this species being common in Cameroun Highlands and Fraser Hill in his 1960s book Common Malayan Wildflowers, but personally i have not seen it at Fraser Hill.

Other companion herbs include an iridescent "blue" begonia by the name of B. pavonina and gesneriads.

Saturday, December 08, 2007

A Hoya?

This is another shy to flower vine. It took a me long time for me to identify it. This leafless green vine is not a hoya, a dischidia or a cynanchum. I first saw it twining over scrub on limestone cliffs at Raleigh beach, Krabi. The impression then was dodder (Cuscuta sp), a parasitic vine commonly found on mangrove and coastal vegetation. But it is too green and has a milky sap, and that helps me to narrow down to milk-weed family (Asclepiadaceae). Again i found it in Halong Bay, Vietnam... twining over Euphorbia antiquorum and other Dracaena. With luck it was in flower and i'm now able to narrow it down to Sarcostemma brevistigma. Unlike Hoya and dischidia, it would never really find a place in collections for lack of flowers and its vining habit. Well it is bless with robustness and a very wide distribution range from India, Nepal, Myanmar and all the way to Thailand, Vietnam and Southern China and is unlikely to face extinction.

Wednesday, December 05, 2007

Euphorbia or Begonia?

This colorful leafy succulent is popular in any sizeable succulent collection. It is probably the closest begonia look alike for a euphorbia species. Euphorbia francoisii is found in under shade from sandy Alluaudia-Didierea thorn forest of southern Madagascar. It is vegetatively allied to Euphorbia decaryi, E. cap-saintmariensis, E. cylindrifolia and E. ambovombensis from the same area. If the plant is seed-grown, there would be a slight basal swelling known as a caudex. The beautiful white-marbled specks, red-hues and veination on the leaves vary from one clone to another. The leaves are very variable and even on the same plant, it is highly dependent on the intensity and the amount of light. Lower leaves being shielded from strong light maybe deep green with little marbling. Generally speaking, high light intensity encourages more white-marbled specks and brings out red hues.

This clone in the photograph below may be a form of E. francoisii v. crassifcaulis 'rubra' with bigger leaves, strong wavy margins and pink veination.
Under equatorial conditions, i learn the hard way after killing cuttings or part of a specimen that it enjoys some shade and will appreciate heat relief under shade when the mercury hits the 35°C or more. Limpy leaves are signs of heat stress or dryness. Caution...if the leaves do not regain turgidness after watering, it maybe under severe heat stress and should be move to a shadier spot for observation and careful watering!

Sunday, December 02, 2007

Dead Leaf Euphorbia

I have this beautiful pot of Euphorbia decaryi var. spirosticha placed strategically near the door to my house. But beauty lies in the eyes of the beholder; a Chinese New Year visitor once asked, "why're you keeping a rotten pile of dead leaves?" Well... i was too upset to correct her. Wait until she got caustic sap white from this plant on her hands, she would realize that it is far from dead.
Surely, if the visitor had looked closer... she would have seen the fresh green new growth! This cryptic mat forming plant is one of my all time favourite Euphorbia. Even if you start off with a cutting or underground stolon or stem with age it forms a mat with new stems spreading out from the center.
E. decaryi comes from the Didierea-Alluaudia forest in Southern Madagascar. It is one of the few Euphorbias with the distinction of being under CITES Appendix 1*. By definition, it is a very endangered and rare species. However, it proves to be very easy and amendable in cultivation and E. decaryi var spirosticha is probably one of the common succulents propagated for sale in nurseries. The type - E. decaryi v decaryi being less attractive is less common in cultivation.

Both varieties are very easy to raise in Singapore - if they are given good bright light and sheltered from rain. They can grow in any mix provided that mix dries out well in between watering. Strong light brings out the brown hues and shade encourages lush green leaves.

*Appendix 1 includes species threatened with extinction. Trade in specimens of these species is permitted only in exceptional circumstances.