Mohd Rosli, Noorfarhana (2007) Miniature orchids associated with mangrove trees at Similajau National Park, Bintulu, Sarawak. [Project Paper] (Submitted)
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Abstract
A study on the identity and morphology of miniature orchids associated with mangrove trees were conducted at Similajau National Park (Latitude 03° 20' 55" N, Longitude 113° 09' 30.6" E) Bintulu, Sarawak. Based on vegetative and reproductive morphology, six species of miniature orchids have been identified; Dendrobium acerosum, D. rosel/um, D. leonis, Bulbopyllum acuminatum, B. purpuracens and B. serratotruncatum. Orchids leaves have variable shapes, leaf surface cells and stomata morphology. Dendrobium acerosum leaves are terete, arranged alternately with spaces between the leaves, D. rosellum and D. leonis have laterally compressed leaves, also arranged alternately but without spaces between the leaves while in B. acuminatum, B. purpuracens and B. serratotruncatum have a single oblong or ovate leaf borne from each pseudobulb. In D. acerosum and D. rosellum, they have leafless component that bears flowers while in D. leonis, flowers are borne from the leaf axis. Basically in the identified orchids, leaf surface varies among species. With the exception of B. acuminatum with pentagonal shape leaf surface cells, most of the Dendrobium acerosum, D. rosellum, D. leonis, B. purpuracens and B. serratotnmcatum have their leaf surface cells that are either angular, tetragonal or rectangular in shape. The leaves are also covered with stomata where in D. acerosum and B. acuminatum the stomata are tetracytic, in D. rosel/um the stomata are paracytic, in D. leonis the stomata are actinocytic while in B. purpuracens and B. serratotruncatum the stomata are anomocytic. Characters of reproductive structures also can be used for identification, e.g. particularly distinctive features of lip, either it is bilobed or not, the colour of sepals and petals which varies from white to yellow with purple flush and the inflorescence either raceme or umbel type. With respect to the pollen morphology, they are oblong in shape but vary in colour from yellow to white. The flower e.g. in Dendrobium acerosum, D. rosellum and D. leonis (but not in Bulbophyllum acuminatum, B. purpuracens and B. serratotruncatum) undergoes resupination during the development. There was no synchronization in flowering pattern for the orchids species identified. Based on observation, a new flower can develop in the same old bract in the next flowering cycle (depending on the species). The development of flowers from buds varies among species where this took about 7 to 12 days and flowers bloomed for 7 to 17 days before they wilted. In general, orchids fruits observed in this present study, took about 38 to 90 days (depends on the species) for the fruit to attain maturity before they dispersed their seeds. The fruits are of dehiscent type, have peculiar characters, when dispersing seeds the fruit opened exposing the longitudinal slits with hairs along the fringe. Depending on the species the fruits have either 3 or 6 longitudinal slits with the sepals and petals usually maintained on the fruit edge.
| Item Type: | Project Paper |
|---|---|
| Faculty: | Faculty of Agriculture and Food Sciences |
| Depositing User: | Mr. Azman Mohamad |
| Date Deposited: | 17 Dec 2024 07:00 |
| Last Modified: | 17 Dec 2024 07:00 |
| URI: | http://psaspb.upm.edu.my/id/eprint/2293 |
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