Difference between revisions of "Dypsis coursii"

Revision as of 22:37, 8 May 2015

Dypsis (DIP-sis) coursii (kohrs'-ee)
Beanivona, Makira Protected Area, Toamasina, Madagascar, photo by Dr. William J. Baker, Royal Botanic Gardens, Kew/Palmweb.
Scientific Classification
Genus: Dypsis (DIP-sis) Species: coursii (kohrs'-ee)
Synonyms
None set.
Native Continent
Africa
Morphology
Habit: Solitary Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Endemic to Madagascar. Only known from the Marojejy area. Moist montane forest or dense sclerophyll forest on ridges; on gneiss and quartzite, alt. (400-) 900-1850 m.

Beanivona, Makira Protected Area, Toamasina, Madagascar, photo by Dr. William J. Baker, Royal Botanic Gardens, Kew/Palmweb.

Description

Solitary palm. STEM 2-8 m, 8-18 cm in diam., near the apex about 2.2 cm in diam. LEAVES about 4 in the crown; sheath 18-36 x 9 cm, with dense reddish tomentum and wax, and with triangular auricles to 5 x 3 cm; petiole 4-27 cm long, 1.1-1.3 x 0.3-0.7 cm in diam., with few scattered scales; rachis 0.4-1 m long (Humbert 23159: leaves 2 m long), in mid-leaf 0.6-1 x 0.4 cm in diam., with scattered scales; leaflets 35-39 on each side of the rachis, in groups of pairs proximally, in 2-7 medially (group interval 2.2-7 cm), the proximal 10-29 x 0.2-1.2 cm, median 12-34 x 1.6-3.5 cm (interval 0.7-1.2 cm), distal 6-17 x 0.4-2.2 cm, main veins 1-5, and thickened margins, ramenta few or none, plus red scattered scales on midrib and veins, apex acute, unequally bifid. INFLORESCENCE infrafoliar, pendulous, branching to (1-) 2 orders; peduncle 23-70 cm, 5-10 x 2-4 mm in diam., with dense to few scattered scales; prophyll 12-26 cm long, borne at 1-6 cm above the base of the peduncle, 1.6-2 cm wide; peduncular bract inserted at 2-17 cm, deciduous, 24 cm long; sterile bract inserted at 19-25 cm, 0.2-3 x 0.6-3 cm; rachis 19-36 cm, glabrous or nearly so, with 6 branched (first order rachis to 20 cm, proximally to 8 x 4 mm diam., with up to 9 rachillae) and 8-22 unbranched first order branches; rachis bracts to 3 mm; rachillae 1-27 cm, 1.2-3 mm in diam., glabrous; triads distant, superficial; rachilla bract about 1 mm, obtuse. STAMINATE FLOWERS yellowish; sepals 1.5-1.6 x 1.3-1.8 mm; petals 2.7-3 x 1.6-2 mm; stamens 6, uniseriate, filaments 1.6-2.8 mm long with triangular base and cylindrical distal half, anthers 1.2-1.6 x 0.6-0.9 mm; pistillode 0.6-1 mm high, 0.4-0.6 mm in diam. PISTILLATE FLOWERS with sepals 1.7-2.8 x 1.5-3.9 mm; petals 4-5 x 2.5-5.5 mm; staminodes 0.3-0.8 mm long; ovary 2.5-3 mm high, 0.9-1.5 mm in diam. FRUIT ellipsoid or slightly obovoid, 20-35 x 15-25 mm, pointed at the base, rounded at the apex; endocarp flaky. SEED obovoid, about 25 x 13-17 mm, pointed at the base, rounded at the apex, the surface slightly channelled, with a sub-basal or lateral depression; endosperm ruminate, the ruminations many, 2-7 mm deep. (J. Dransfield and H. Beentje. 1995)/Palmweb. Editing by edric.

Distinct by its short, wide trunk, the distant groups of densely set leaflets, and large ruminate fruits. (J. Dransfield and H. Beentje. 1995)/Palmweb.

Culture

Cold Hardiness Zone: 10a

Comments and Curiosities

A curious montane species, with a short, wide trunk. The name refers to one of the collectors, G. Cours, who made many good palm collections between 1939 and 1952. (J. Dransfield and H. Beentje. 1995)/Palmweb.

Conservation: Vulnerable. Distribution area small, but protected. Numbers unknown, but thought to be low. (J. Dransfield and H. Beentje. 1995)/Palmweb.

"Last word on the matter was that when Dr. John Dransfield was in Jeff's garden (Floribunda) and saw his flowering plants he felt pretty confident it was Dypsis marojejyi. When you read POM a big difference is, that it says Coursii is infrafoliar with shorter inflorescence, and Marojejyi is interfoliar with longer inflorescence. Every plant labeled as Marojejy that I have seen personally or in pictures in flower is interfoliar. And the inflorescence is certainly pretty large." (LJG)