Chrysalidocarpus robustus (Hodel, Marcus & J.Dransf.) Eiserhardt & W.J.Baker

Diagnostic

Dypsis ifanadianae affinis sed trunco maiore, vaginis foliorum maioribus cera alba et tomento rubiginoso, rhachidibus foliorum longioribus pinnis pluribus, inflorescentiis 4 ordines ramificantibus differt; D. tsaravoasirae affinis sed foliis spiraliter dispositis, vaginis foliorum cera alba et tomento rubiginoso, rhachidibus foliorum longioribus, inflorescentiis maioribus interfoliaceis 4 ordines ramificantibus differt.

General Description

Solitary, robust tree palm. Trunk 1.4 m tall, 36.4 cm diam.l m above ground, flaring to 64 cm diam. at ground level; internodes 5-6.5 cm, dark green covered with white waxy indumentum, aging to brownish gray with vertical fissures; leaf scars 3.8 cm wide. Leaves 14, pinnate, ascending; base massive, 95 cm long, 25 cm wide adaxially and 40 cm wide abaxially at pinnae, flaring out to 115 cm wide in proximal 35 cm, thick, + woody, 12 cm think at pinnae, 3-4 cm thick midsheath, 1.5 cm thick at proximal margins, 3-5 mm thick at distal margins, orange-brown adaxially, densely covered with white waxy indumentum densely punctuated with ragged, branched, lacerate, fringed, reddish brown scales 2-2.5 mm high, sometimes with auricles to 8 cm high on either side of rachis; rachis to 4.6 m long, distally twisting nearly 180°, 25 cm wide and broadly channeled adaxially at sheath, 40 cm wide and broadly rounded abaxially at sheath, both surfaces green and densely covered with white waxy indumentum and reddish brown tomentum, adaxial channel to 4 cm deep but gradually narrowing and becoming shallower until at mid-blade a flattopped ridge and then 40 cm distally of midblade into a narrow sharply angled ridge 1.5 cm high, gradually dissipating near tip, rachis 4 cm wide midblade and 3 mm wide at tip, rounded abaxially and covered with white waxy indumentum, freshly cut surfaces with pinkish tinge; pinnae 135-140 per side, regularly arranged but twisting rachis and ascending pinnae with drooping tips imparting the appearance of being irregularly arranged and lending a somewhat plumose effect to the blade, most proximal 63 x 1.3 cm, at 1-2 m distally of sheath 120 x 4.5 cm, at 3 m distally of sheath 80 x 5 cm, most distal 18 x 0.5 cm, thick, coriaceous, dark glossy green adaxially with prominently raised light green midrib and thickened marginal nerves, 5-6 inconspicuous nerves between midrib and each margin, green with distinct glaucous bloom abaxially and prominently raised midrib, scattered light brown to tan, ragged, lacerate, medifixed ramenta 4-10 mm long on midrib abaxially and these most common in mid-blade and in proximal 30 cm of each pinna, pinnae 4-7 cm apart in proximal meter, 3-4 cm apart mid-blade to tip, forward pointing, spreading and flat with slightly drooping tips in proximal 1 m, at mid-blade ascending off rachis and blade + V-shaped, tips drooping, pinnae flat in distal 1 m. Inflorescences protandrous, interfoliar, branched to 4 orders, most proximal branches of first three orders of branching the largest and most complex and progressively becoming smaller and less complex distally until most distal represented by simple rachillae; peduncle 1 m long, 9 cm wide, 5 cm thick, arcuate, green, covered with patchy reddish brown tomentum; only tip of prophyll or 1st peduncular bract seen, this portion 18 cm long, green, stiff, coriaceous, flattened, 2- keeled, sparsely covered with reddish brown tomentum; 3 rudimentary peduncular bracts present, most distal 10 cm below most proximal branch, 1.5 cm high, next lowest 20 cm proximal below most proximal branch, 2.5 cm high, most proximal 38 cm below most proximal branch, 18 cm long; rachis 1.7m long, green with some reddish brown tomentum, 43 1st order branches; most proximal 1st order branch with sub-peduncle 18 cm long, 4.5-5.7 cm wide, flattened, 2.3 cm thick, sub-rachis 97 cm long with 32 2nd order branches; most proximal 2nd order branch with sub-peduncle 12.5 cm long, 1.2-1.9 cm wide, flattened, 1 cm thick, subrachis 30.5 cm long with 15 3rd order branches; most proximal 3rd order branch with subpeduncle 2.5 cm long and branched into 2-3 rachillae; all branches and rachillae of all orders subtended by bracteoles; rachillae (12-)20-25 cm long, 4 mm diam., spreading, ± stiff but drooping and yellow-green in fruit. Flowers (fresh flowers at anthesis not seen) borne in triads in cleft-like pits 1.5 mm high, 3 mm wide, 1 mm deep, proximal lip of pit cliff-like, slightly mucronate, triads 3-5 mm apart proximally, 2-3 mm apart distally; each staminate flower subtended by a small, thin, crescent-shaped, nearly transparent bracteole 0.2 mm high on outer side; pistillate flower subtended by 2, thin, light green, nearly transparent, imbricate bracteoles 0.5 mm high. Fruits 14 x 12 mm, very broadly ellipsoid, orange, stigmatic remains basal, just above perianth; mesocarp mucilaginous, 1 mm thick. Fruiting perianth 6.5 mm wide; sepals imbricate in basal 1/5, very briefly connate, broadly rounded apically, 2 x 3 mm; petals imbricate in basal 1/3-1/2, very briefly connate, 3 x 4-5 mm, rounded-triangular; staminodes 6, triangular, 0.8-1 mm high. Seeds 1 1 x 9 mm, obovoid-ellipsoid; endosperm homogeneous; embryo slightly distal of middle.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/17060763/17060794

Conservation

CR - critically endangered