Capparis diffusa Ridl.

Capparis diffusa Ridl. (Ridley 1911: 68.).

Type material

MALAYSIA • Perlis, Bukit Lagi; Mar. 1910; Ridley 15174; holotype: SING [SING0056837]; isotype: K [K000643988].

Other material examined

VIETNAM – An Giang Province • Mont de Chaudoc; June 1876; Harmand 592; P [P04022334, P04746968, P04746969]. – Dong Nai Province • Tan Phu District, Cat Tien National Park; 11°25′9.34″ N, 107°25′7.82″ E; 28 Sep. 2005; N. V. Du et al. HNK 863; HN, K [K000577054] • Tan Phu District, Cat Tien National Park; 11°27′31″ N, 107°22′22″ E; 28 Sep. 2005; N. V. Du et al. HNK 947; HN, K [K000577053].

Description

Shrubs or climbers. Twigs puberulous, later glabrescent. Stipular thorns recurved, 1–3 mm long, in some cases lacking. Petiole 2–5 mm long. Leaf blade herbaceous, 1.7–3.5 times as long as wide, 4–9.5(–11.2) × 1.2–4(–5) cm; base rounded or acute, top acute or subacuminate, in some cases notched; surfaces glabrous; nerves 5–10 pairs. Flowers in terminal subumbels 3–5(–10)-flowered, or the umbels lateral on short twigs; pedicels 2–5 cm long, glabrous; sepals ca 4–5 × 2–4 mm, glabrous, inner pair ciliate; petals white, oblong, ca 4–6(–8) mm long, inside pubescent; stamens 12–15(–20); gynophore ca 1–1.8(–2) cm long, glabrous; ovary subglobose, ca 1 mm long, glabrous. Fruit globose, ca 7–8(–10) mm in diameter.

Distribution and ecology

Malaysia, Thailand, Vietnam, Indonesia (Sumatra). The occurrence of the species in Cambodia, reported by Jacobs (1965), was not confirmed by Fici (2023). In Vietnam recorded by Ban & Dorofeev (2003) in Thua Thien-Hue, Khanh Hoa and An Giang provinces. During the present research also material from Dong Nai Province was examined. Evergreen forests, forest edges and thickets, on limestone at low elevation (Jacobs 1965; Ban & Dorofeev 2003). In Dong Nai Province collected in closed evergreen forest on black soil, at 145 m a.s.l. (N.V. Du et al. HNK 947), and in semi-evergreen forest on alluvial soil, at 120 m a.s.l. (N.V. Du et al. HNK 863).

Phenology

Flowering from December to May (Jacobs 1965); based on Ban & Dorofeev (2003) fruiting in May– June in Vietnam, but fruiting material was collected in September in Dong Nai Province (N.V. Du et al. HNK 947 & 863).

Provisional conservation status

Least Concern (LC) according to IUCN Red List Categories and Criteria (IUCN 2012). Based on the available data, no risks were detected for the populations of the species in the study area.

Vernacular name

ʻCáp tràn' (Ban & Dorofeev 2003).