Chrysalidocarpus rabepierrei (Eiserhardt & W.J.Baker) Eiserhardt & W.J.Baker

Eiserhardt, W.L., Dransfield, J., Rakotoarinivo, M. et al. (2018). Four new species of Dypsis (Arecaceae: Arecoideae) from Madagascar. Kew Bulletin 73: 44. https://doi.org/10.1007/s12225-018-9776-z

Type

Madagascar, Antsiranana, Sava, Antalaha, Vinanivao, Tanany Rabepierre (Ankorabe), 74 m a.s.l., 15°43'41"S, 50°12'50"E, 18 Nov. 2015, Eiserhardt et al. 138 (holotype K!, isotypes MO!, P!, TAN!).

Morphology General Habit

Slender, solitary, mid-storey palm 4 – 6 m tall (rarely to 20 m), bearing 6 – 10 spirally arranged leaves in crown

Morphology Stem

Stem 2.5 – 7 cm in diam., green; leaf scars prominent; internodes 1.5 – 10 cm; covered in white indumentum

Morphology Leaves

Leaf to 250 cm long including petiole; sheath 35 – 60 cm long, blackish green with white indumentum, apically also with blackish-brown scales, young sheaths bright red, crownshaft to 70 cm long, 4 – 5 cm wide; petiole 41 – 70 cm long, concave on adaxial surface, green, basal portion sparsely covered with blackish-brown, peltate scales; leaflets 33 – 45 each side of rachis, regularly arranged in one horizontal plane, slightly arching, borne 0.5 – 5 cm apart, adaxially glaucous and abaxially reddish brown when dry, glaucous on adaxial surface; basal leaflets 35 – 56 cm long, 0.6 – 1.1 cm wide, linear; middle leaflets 43 – 61 cm long, 1.2 – 1.6 cm wide, linear, transverse veinlets inconspicuous; apical leaflets 12 – 17 cm long, 0.4 – 0.6 cm wide, linear, not united

Morphology Reproductive morphology Inflorescences

Inflorescence 70 – 90 cm long, interfoliar, more or less horizontal, tassel-shaped, branched to 2 orders, pale yellow; prophyll 50 – 62 cm long, 5 – 12 cm wide, green turning pale brown at anthesis, cucullate, glabrous; first peduncular bract similar to prophyll, persistent, c. 45 cm long, c. 10 cm wide, attached 6 – 7 cm below first primary branch; two additional inconspicuous peduncular bracts present, 0.3 – 1 cm long; peduncle 42 – 45 cm long, 1 – 2 cm wide, glabrous; primary branches c. 20, to 18 cm long, c. 0.5 cm apart, with up to 8 rachillae; rachillae 8 – 15.5 cm long, 1.5 – 3 mm in diam.; rachilla bracts inconspicuous; triads c. 2 mm apart, spirally arranged

Morphology Reproductive morphology Flowers

Female flower not seen Male flower 3.9 – 4.4 mm long, 3.2 – 3.4 mm in diam. at anthesis; sepals 3, 1.8 – 2.3 mm long, 1.8 – 2 mm wide, cucullate with sharp keel; petals 2.5 – 3.2 mm long, 2.5 – 2.8 mm wide, rounded; stamens 6; filaments 1.9 – 2.5 mm long, free, spindle-shaped; undehisced anthers 2 – 2.2 mm long, c. 0.9 mm wide; dorsifixed; dehiscence latrorse; connective dark brown; pistillode 2.8 – 2.9 mm long, 0.9 – 1.1 mm in diam. at base, bottle-shaped, dark brown

Morphology Reproductive morphology Fruits

Fruit not seen

Morphology Reproductive morphology Seeds

Seed not seen

Distribution

Known only from the type locality and nearby places on the eastern side of the Masoala peninsula (Madagascar).

Ecology

Primary lowland humid forest.

Vernacular

Lafaza maitso or ovojavavy (Betsimisaraka).

Conservation

Critically Endangered (CR) [B2a,b (iii)+D]. The only known population is located at the edge of the Masoala National Park where the local population has some access to the natural resources. It is predicted that the quality of the habitat declines and may affect the long-term survival of the less than 20 individuals seen.

Note

This is a fairly inconspicuous medium-sized understory palm, the most outstanding feature being the intensely waxy-white crownshaft, and the tassel-shaped yellow inflorescence with long cucullate prophyll and peduncular bract. On morphological grounds its relationships lie with informal Group 3 of Dransfield & Beentje (1995) where it superficially resembles a single-stemmed form of Dypsis onilahensis (Jum. & H. Perrier) Beentje & J. Dransf., or D. baronii, but is immediately set apart by the unusual tassel-shaped inflorescence. The species is named after Monsieur Rabe Pierre who kindly allowed us access to his land both in 1996 and 2015, guiding both expedition parties to palm-rich areas from which the type specimens of Dypsis rabepierrei, D. ovojavavy (both described here), D. metallica Rakotoarin. & J. Dransf. and D. vonitrandambo Rakotoarin. & J. Dransf. (Rakotoarinivo & Dransfield 2010) were collected. This palm is distinct from other Dypsis species in Group 3 sensu Dransfield & Beentje (1995) being solitary, having a tassel-shaped inflorescence with prophyll and peduncular bract of very similar appearance and length, and glabrous leaflets.