Guihaia grossifibrosa 知識
Unbranched dioecious fan palm, solitary or in clumps of 2–5 individual stems of different height, rarely forming ± dense groups with more than 5 trunks, each terminated by a very open crown. Trunk rigid, erect, 0.5–2.5 m tall (female samples usually more compact and smaller, up to 2 m high) in upper part densely covered with persistent leaf sheaths, 4–8 cm in diam., bare near the ground, 1.5–2.5 cm diam., with internodes 1–1.5 cm long. Leaves 6–12(14) in crown; sheaths, when young narrow, cylindrical, hardly splitting, 18–12 cm long, 1–1.5 cm wide, dull brown, with dull gray-brown papyraceous hairs; sheaths of old leaves widening to 6–8 cm, deep brown to black, glabrous, shortly cylindrical to broad ovate, inflated, split into linear, very rigid, coarse, woody, wire-like anastomosing segments, often disintegrating into free, more or less reflexed spike-like tips, surrounding stem with wire-like rigid netlike covering; ligule-like tip deep brown to black, glabrous, erect, 6–15 cm long, with very rigid and hard, beak-like apex, at the base dissected into network of numerous anastomosing linear rigid segments; petiole narrow, slender, rigid, 0.5–1 m long, 2–3 mm broad, subterete, broadening and flattened to the base up to 5–6 mm wide, slightly curved in basal portion (strongly curved in old leaves), ± straight toward the leaf blade, glabrous, smooth along margin, green or dull brown near trunk; adaxial hastula semi-circular, erect, 2–2.5 mm high, sometimes irregularly dissected into two unequal lobes, hairy when young with dull gray-brown papyraceous caducous hairs, on old leaves glabrous; leaf blade leathery, dark green above, light green (sometime whitish) below, broadly fan shaped in outline, 40–45 cm long from hastula, palmately segmented from near the base into 6–10(12) unequal segments, each segment linear to elliptic, (0.8)1–3(6) cm wide, broadest segments commonly partially dissected from periphery, smooth (in male samples) to sparsely, very finely denticulate along margin (in female samples) with 1 to 6(10) prominent longitudinal veins, longitudinally folded, sometimes slightly narrowing to acute apex, hairy above (in young leaves) at the base with sparse short papyraceous dull gray-brown hairs. Inflorescence 1–2(3), branched to 3(4) order, situated in leaf axils near the apex of the trunk, 40–70 cm long, with light dull brownish to deep brown, rigid, narrowly lanceolate smooth laterally compressed basal bracts; basal bracts 2(3), 15–30 cm long, 1–2 cm wide, densely hairy with dull gray-brown short papyraceous hairs (when young) or glabrous (when old), tubular in basal portion, acuminate at the apex; peduncle erect, very rigid, 20–30 cm long, 5–7 mm broad, oval in cross section, enveloped by basal bracts; rachis very rigid, 20–25 cm long, 3–4 mm wide, slightly flexuous, with 2–3 main branches, with 1 rigid brown bract similar to basal inflorescence bracts, hairy (when young), 6–9 cm long, 4–8 mm broad; rachillae numerous, (0.5)1.5–8(10) cm long, rather straight, rigid, with numerous, sessile, densely spirally arranged, yellowish to yellow-green flowers, each flower with very small insignificant triangular bracteole. Flowers unisexual, sessile, radially symmetrical; male flowers shortly cylindrical or broadly shortly conical, 2.4–2.6 mm long, about 2 mm wide, campanulate; sepals 3, free, scale-like, ovate to subquadrate, 2–2.2 mm long, 2–2.4 mm broad, indistinctly trilobed or broadly tridentate at apex, thickening into broad inflated broadly triangular woody base; petals 3, narrowly triangular, 2.4–2.6 mm long, 1.5–1.8 mm wide, with orbicular apex, three times longer than sepals, inside at the apex with prominent hemispherical cushion, connate from the base to 3/4 their length into conical fleshy tube, finely longitudinally wrinkled; stamens 6, ± similar, in two whorls, not exceeding thepetals, filaments adnate to the perianth, anthers subsessile oblong reniform, 0.3–0.4 mm long, 0.2–0.3 mm broad, dehiscing longitudinally along lateral margin; pistillodes absent; female flowers shortly cylindrical to subglobose, 2–2.2 mm long and broad; sepals 3, free, scale-like, broadly ovate to suborbiculate, 1.4–1.6 mm long and broad, thickened at the base, finely verrucose outside; petals 3, ovate, about 2 mm long, 1.8 mm wide, outside in upper part with transverse low inflated band, at basal half smooth or indistinctly longitudinally wrinkled, in apical portion with irregular transverse rough wrinkles, deeply connate into rigid woody cupule with only free roundish apices of petals; staminodes 3 (rudiments of stamen of inner whorl), small, tooth-like; gynoecium unknown. Fruit 1-seeded; young fruit briefly stalked, ovoid, with thin exocarp and with few weak fibers in mesocarp; old ripe fruits (fallen on ground) black, spherical, about 1 cm in diameter.
Guihaia grossifibrosa has a dwarf habit with trunk 1–2 m tall (rarely up to 2.5 m) covered with unusual rigid scale-like leaf sheaths rather reminiscent of dragon scales. It is a highly endangered species of the shrub stratum in primary limestone forests on ancient karst limestone hills and low ridges 500-1100 m asl. This palm never forms large dense populations and occurs commonly as scattered individuals or loose groups including usually not more than 3–5 growths of different heights. Male plants are usually a little bit taller, while female ones are shorter, more compact and robust. The plants are commonly rooted in deep vertical pockets in eroded limestone filled with rich deep brown well structured friable soil covered with leaf litter. Cultivation of this palm may be an important factor for its protection. Drainage of the karst limestone ground is very sharp, and rain water never accumulates in soils even during heavy rains.
へのネイティブ, China, Vietnam
場所： Vietnam, China (22.951311°N, 107.687988°E)