Rhapis gracilis

Rhapis (RAH-pis) gracilis (grah-SIHL-iss)
Queensland, Australia. Photo by Colin Wilson.
Scientific Classification
Genus: Rhapis (RAH-pis) Species: gracilis (grah-SIHL-iss)
Synonyms
None set.
Native Continent
America
Morphology
Habit: Clustering Leaf type: Pinnate
Culture
Survivability index
Common names
细棕竹 xi zong zhu

Habitat and Distribution

China Southeast, Hainan, Laos, South China, Guangdong; Laos.

Vicinitie of A Rem Village (17º23'32N, 106º12'46E), Tan Trach Municipality, Bo Trach, Vietnam. Photo by Dr. Nguyen Tien Hiep, Royal Botanic Gardens, Kew/Palmweb.

160 m at the foot of limestone hills. Lowland forests on limestone slopes; below 900 m. Guangdong, Guangxi, Hainan [Vietnam].

Description

Stems are slender to 10 mm in diameter, covered in fine fibred leaf sheaths. The leaf is palmate with three to four segments, each leaflet is up to 30 mm wide having three to four major ribs and the leaflet tip is sharply toothed. The inflorescence is about 200 mm long, either unbranched or sparsely branched near the base. Fruits are globular and 8-9 mm in diameter.

Stems clustered, rhizomatous, forming colonies, to 2 m tall, to 0.5 cm in diam., covered with persistent, fibrous leaf sheaths. Leaf sheaths with fine, black or brown fibers producing a square mesh; ligules persistent; blades split to base, divided into 2-4 segments, these with curved sides and ± pointed apices, to 20 × 3.5 cm. Inflorescences borne among leaves, branched to 2 orders; bracts tubular, sheathing; rachis to 20 cm; rachillae 2-3 cm, ± glabrous; male flowers to 4 mm; sepals united into a tubular, 3-lobed calyx; petals united into a tubular corolla with a 3-lobed, valvate apex; stamens 6, borne in 2 series; filaments not keeled adaxially; female flowers similar to but shorter than male. Fruits developing from 1 carpel, blue-green, globose, to 0.8 cm in diam., borne on a short stalk. (efloras.org)

Stem height not recorded, with sheaths 6–8 mm diam. without sheaths 3–5 mm. Leaf sheath with very fine, wavy fibers with a square mesh, ligule sometimes remaining intact at maturity; petiole to 1.8 mm wide, margin usually smooth sometimes bearing minute brown papillae; blade small, with V-shaped outline, without a palman, segments 2–4, folds 11–15, longest to 180 mm, apices oblique with secondary splitting, primary splits to within 3–15 mm of the blade base, both surfaces similar in colour, green with white tinge, transverse veinlets very conspicuous. Inflorescence, the male and female similar in general appearance with few rachillae, branching to 2 orders; prophyll and 2 rachis bracts similar in appearance, tubular, overlapping the base of the next bract, medium thickness, reddish brown, inner surface shiny, outer dull, lacking tomentum; rachis overall length to 200 mm, narrow, to 2 mm diam., few rachillae, occasionally with sparse tomentum where the rachis is adnate to the peduncle, medium brown. Flowers, 2–3 mm apart. Male flowers obovoid, to 4.3 × 2.2 mm; calyx to 2 mm, lobes acute to 1.1 mm with regular margin; corolla with a receptacular-stalk to 1 mm; filaments, shorter row to 1.2 mm, longer to 1.6 mm, to 0.3 mm diam. Female flowers only immature seen, to 3.1 × 2.1 mm; calyx to 2.6mm, margin regular, lobes acute to 1.1 mm; corolla with a receptacular-stalk to 0.2 mm. Fruit to 8 mm diam., borne on a receptacular-stalk to 2.5 mm; epicarp dull, papillose. (L. Hastings, A Revision of Rhapis, the Lady Palms. 2003)/Palmweb. Editing by edric.

This species is similar vegetatively to Rhapis subtilis but differs in the flowers, notably in possessing acute calyx lobes. Burret recorded a fruit receptacular-stalk to 5 mm, a character which also distinguishes it from R. subtilis. Only two herbarium specimens were available for study, including an isotype. The heights of the specimens were not recorded on the labels; however, it is likely from the other measurements taken that this is smaller than Rhapis subtilis. According to specimen label data the fruit is green-blue. (L. Hastings, A Revision of Rhapis, the Lady Palms. 2003)/Palmweb.

Culture

Cultural requirement are said to be similar to the other species. Cold Hardiness Zone: 9a

Comments and Curiosities

A very rare species from Southern China with slender canes and small leaves with only 3-4 segments. (RPS.com)