Chrysalidocarpus onilahensis Jum. & H.Perrier

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: threatened. Confidence: confident

Distribution

NW and W Madagascar and South-Central Madagascar.

Biology

Riverine forest, alt. 50-300 m (in the North) or riverine to evergreen forest (remnants) at 750-2400 m (Mountains of the Centre-North; Centre-South). Humbert states the palm is abundant on the rocky banks at flood level of the Analabe River in the north.

Vernacular

Kindro (Antankarana); Sihara (Bara).

General Description

Clustering palm in tufts of 3-10 (occasionally appearing as solitary, fide Humbert). STEMS 2-20 m high, 2.5-15 cm diam. (-30 cm, fide Perrier), distally stepped and ringed; internodes 0.3-20 cm, proximally grey, distally dark green, nodal scars 0.2-0.5 cm, white. LEAVES 5-7 in the crown, gracefully arching to half-pendulous; sheath 18-60 cm, 4.5-6 cm diam., open for about one third, abaxially dark grey-green, pale green to pale brown but nearly always with a white waxy bloom, distally reddish-pubescent but glabrescent, adaxially rich red-brown, without or with only slight ligules to 1.5 x 4 mm; petiole absent or up to 40 cm long, proximally 1.2-2.3 x 1-1.5 cm with an adaxial triangular swelling as a sheath lining extension, distally 1.3-1.7 x 0.6-1.6 cm, slightly channelled with sharp edges, glabrous or with reddish scales on both surfaces, dark green with flecks of dark brown; rachis 1-1.8 m long, proximally channelled, in mid-leaf keeled and 0.7-1.7 cm wide, with reddish scales or glabrous; leaflets 42-64 on each side of the rachis, regular, in one plane, opposite leaflets also in one plane (in Isalo) or at an angle of 90° (elsewhere), slightly pendulous, curving or stiff with only the distal part arching, dark green and hardly shiny adaxially, mat and glaucous abaxially, the proximal (22-) 38-106 x 0.2-2 cm (interval up to 19 cm), median 35-75 x 0.8-2.5 cm (interval 0.8-4 cm), distal 8-44 x 0.2-1.9 cm (the distal pair joined for up to 2 cm), main veins 1-5, rather faint with only the midrib adaxially prominent, adaxially with proximal or scattered red-brown rather large (6-30 mm) ramenta on the midrib, otherwise glabrous, apices long- atten-uate, bifid. INFLORESCENCE interfoliar or infrafoliar at anthesis, infrafoliar at the fruiting stage, curved with spreading rachillae, branched to 2 orders (once to 3 orders in Humbert 7025); peduncle 15-78 cm long, usually curving through 180°, proximally 0.6-4 x 0.4- 1.2 cm diam., distally 0.9-4 x 0.6-1.5 cm, with scattered scales or glabrous; prophyll 11-87 cm, borne at 3.5-45 cm above the base of the peduncle, 2-6 cm wide with narrow wings to 3 mm wide, split only at the apex for some 3 cm or open for up to 50%, yellow turning pale brown with scattered reddish scales distally; peduncular bract often quickly deciduous (in trees with long peduncles), inserted at 6-42 cm from the base of the peduncle, 18-55 cm long, beaked for 0.5-4 cm, splitting completely (except for the beak), adaxially glabrous and redbrown, abaxially pale green with scattered red-brown laciniate scales; non-tubular peduncular bracts usually two near the peduncle apex, 0.2-2.5 x 0.5 cm; rachis 16-40 cm long, waxy pale green, with 5-15 branched and 8-12 unbranched first order branches, the most proximal with a rachis of up to 7.5 (-26.5 in Humbert 18432) cm and 0.8-1.7 x 0.3-0.5 cm proximally, with 4-12 rachillae; rachis bracts up to 1 cm; rachillae 6-30 cm long, sinuous distally, 1.5-4.5 mm diam., glabrous, with distant triads in slight pits with an acute triangular rachilla bract 1-1.5 mm. STAMINATE FLOWERS creamy green or yellowish, with a sweet or unpleasant smell, with sepals 1.4-2.9 x 1.5-2.8 mm, concave, acute, keeled and gibbous; petals free or connate up to 1 mm, 2.2-4.2 x 1.5-3.4 mm, ovate and concave, acute; stamens 6, uniseriate or very vaguely biseriate (then with 0.1 mm difference in insertion and a callus between the filaments), filaments 1.2-3 mm long and thinly cylindrical, anthers 1.3-2.8 x 0.6-1.3 mm, dorsifixed, versatile, the locules parallel or proximally slightly divergent; pistillode 1-2.3 x 0.4-1.3 mm. PISTILLATE FLOWERS with sepals 2.2-3.1 x 2.2-3.2 mm, rounded; petals 2.5-3.5 x 2.5-4 mm; staminodes 0.3-1 mm; gynoecium 2.8-3.5 x 1.5-2.9 mm. FRUIT yellow, waxy?, ovoid to subglobose, 10-18 x 7-15 mm, the apex rounded; endocarp very fibrous with almost free fibres. SEED black, 9-17 x 6.5- 12 mm, ellipsoid with pointed base and rounded apex, and a small subbasal depression; endosperm homogeneous. EOPHYLL bifid.

Conservation

Vulnerable. Though the distribution area is fairly large, the habitat is prone to destruction by fire. Numbers are estimated at less than a thousand. The population in the Isalo National Park is well-protected, but numbers less than a few hundred individuals.