Dictyosperma Album

''Dictyosperma'' is a monotypic genus of flowering plant in the palm family found in the Mascarene Islands in the Indian Ocean (Mauritius, Réunion and Rodrigues). The sole species, ''Dictyosperma album'', is widely cultivated in the tropics but has been farmed to near extinction in its native habitat. It is commonly called princess palm or hurricane palm, the latter owing to its ability to withstand strong winds by easily shedding leaves.Riffle, Robert L. and Craft, Paul (2003) ''An Encyclopedia of Cultivated Palms''. Portland: Timber Press. / It is closely related to, and resembles, palms in the genus '' Archontophoenix''. The genus is named from two Greek words meaning "net" and "seed" and the epithet is Latin for "white", the common color of the crownshaft at the top of the trunk.

Description

The ringed trunks are solitary at 15 cm in diameter with a slight bulge at the base, occasionally reaching up to 12 m in height. The crownshaft is over a meter tall, swollen at the base, and covered in white wax— which has given the palm its epithet ''album''— and small, matted brown hairs, producing a rounded leaf crown 4.5 m wide and 3 m tall. The 2.5 to 3 m leaves are borne on short 30 cm petioles; the arching leaflets are pointed at the apice, from 60 – 90 cm, dark green in color, and emerge from the rachis in a single plane.

On flowering, they produce up to six inflorescences which ring the trunk below the crownshaft, branched to one order, with white to yellow flowers, which are male and female; both pistillate and staminate flowers have three sepals and three petals, the former being smaller than the latter. The ovoid fruit ripen to purple or black in color, containing one brown, ellipsoidal seed.

Three varieties are currently recognized:
* ''Dictyosperma album'' var. ''album'' (Bory) Scheff. - Mauritius, Réunion
* ''Dictyosperma album'' var. ''aureum'' Balf.f. in J.G.Baker - Rodrigues Island
* ''Dictyosperma album'' var. ''conjugatum'' H.E.Moore & J.Guého - 2 remaining specimens on Île Ronde of Mauritius (Characterised by shorter trunk and white leaf-scar)

Distribution and habitat

Living in the coastal forests of the Mascarenes, they experience warm temperatures, high humidity and regular rainfall.Uhl, Natalie W. and Dransfield, John (1987) ''Genera Palmarum - A classification of palms based on the work of Harold E. Moore''. Lawrence, Kansas: Allen Press. /

''Asterolecanium dictyospermae''

'' Asterolecanium dictyospermae'' is a species of sap sucking scale insect found only on Île Ronde on the two remaining ''Dictyosperma album'' var. ''conjugatum'' specimens. It apparently evolved on Île Ronde and became restricted to feeding upon the island's endemic variety, and due to interbreeding (between varieties) on Mauritius itself which jeopardized reproductive potential, the scale insect increased in population as a result of stress upon the host, which then threatens the existence of both host and scale insect.
Image:Dictyosperma album big foot with roots.JPG, Trunk base and roots
Image:Dictyosperma album seedlings.JPG, Seedlings with bifid eophyll
Image:Dictyosperma album1.JPG, Leaf crown
Image:Dictyosperma_album_var._conjugatum.JPG, Dictyosperma album var. conjugatum

References

External links

''Dictyosperma images''

''Dictyosperma'' on NPGS/GRIN
*

GBIF Portal

Fairchild Guide to Palms: ''Dictyosperma''



Floridata site

{{Taxonbar, from1=Q16060603, from2=Q3141626

Endemic flora of the Mascarene Islands
Areceae
Monotypic Arecaceae genera