Ziziphus angustifolia (Miq.) Hatus. ex Steenis

Cahen, D., Rickenback, J. & Utteridge, T.M.A. A revision of Ziziphus (Rhamnaceae) in Borneo. Kew Bull 76, 767–804 (2021). DOI: https://doi.org/10.1007/s12225-021-09970-3

Type

Indonesia, Sumatra, Priaman, [collector unknown] HB 2501 (lectotype, selected here: L [L 0013794]; paralectoype: L [L 0931291]).

Morphology General Habit

Tree, to at least 25 m high, unarmed, girth to 1.5 m in diam.; bole ± straight, to at least 15 m high, buttresses sometimes present, low, 1 × 1 (– 1.5) m

Morphology General Bark

Bark usually greyish-brown, smooth, not peeling, to at least 12 mm thick; lenticels visible, in longitudinal rows, yellowish-brown, inner bark yellowish or pale pink grading into orange near cambium, to at least 2.5 mm thick; cambium pink, orange or red, to at least 1.25 mm thick

Morphology General Wood

Sapwood yellowish-brown, hard; heartwood dark brown, hard

Morphology Branches

Branchlets terete, with longitudinal striations and visible lenticels, hairs absent to sparse (– dense), hairs short, c. 0.1 mm long, appressed

Morphology Leaves Stipules

Stipules not transformed into spines, early deciduous, narrowly triangular, c. 2 mm long, densely hairy

Morphology Leaves

Leaves weakly discolorous, drying greenish-brown, blade ± symmetric, (narrow) elliptic-oblong, 7.5 – 22.5 × 2.5 – 8.6 cm, chartaceous to subcoriaceous, apex attenuate to acuminate, base (cuneate –) obtuse to rounded, ± symmetric, margins usually subentire, sometimes clearly serrate, each serration topped by a minute protruding callosity that dries darker than the lamina, c. 0.1 mm long; primary veins 3, impressed adaxially, raised abaxially, hairs sparse (– abundant) along primary veins abaxially, c. 0.2 mm long, ± appressed, reddish some whitish; strong marginal veins coming off the outside of the two outer main veins > 20 on either side, all ending in a distinct intramarginal vein running along the leaf margin, angle of divergence with outer main veins c. 65°; transverse veins between the main veins conspicuous, coming off midrib at c. 90°, raised (readily felt by touch), spaced by (2 –) 4 (– 10) mm from each other; higher order reticulations visible; lamina glabrous (– abundantly hairy) abaxially; no domatia visible; petiole subterete, 5 – 12 mm long, glabrous

Morphology Reproductive morphology Inflorescences

Inflorescence of axillary short-pedunculed, almost fascicle-like cymes, often branched, usually c. as long as subtending leaf’s petiole, 6 – 12 flowers in each cyme; pedicels to 2 – 3 mm long, hairs dense; bracteoles entire, narrowly triangular, c. 1 mm long, hairy

Morphology Reproductive morphology Flowers

Flower hypanthium densely hairy on the outer surface; sepals triangular, c. 2 mm long, glabrous and keeled adaxially; petals clawed, c. 1.4 mm long, obcordate; stamen filaments flat, subulate, c. 1.2 mm long, anthers c. 0.4 mm long, exceeding petals; nectary disk pentagonal, rugose, appearing ± 20-pitted, glabrous, annulus strongly raised and sheathing style; style arms (2 –) 3 (– 4), c. 0.5 mm long, diverging, not expanding at apex, glabrous ovary partially immersed

Morphology Reproductive morphology Fruits

Fruit a drupe, ripening yellowish-green, pinkish or red, (1.3 –) 1.6 (– 1.9) × (0.8 –) 1.1 (– 1.5) cm, obovoid [wider towards apex], glabrous; fruiting pedicels c. 3 – 6 mm long; hypanthium remains annular at base of fruit.

Distribution

Brunei, Indonesia (Java, Kalimantan, Maluku, Sulawesi, Sumatra, West Papua), Malaysia (Peninsular Malaysia, Sabah, Sarawak), Myanmar, Papua New Guinea, Philippines (Biliran, Leyte, Luzon, Masbate, Mindanao, Mindoro, Palawan, Samar), Solomon Islands, Thailand.

Ecology

Borneo lowland forests; extending to montane rain forests; alt. 0 – 1500 m.

Conservation

Least Concern (LC). Ziziphus angustifolia is widely distributed from southern Thailand to the Solomon Islands. It is commonly collected in lowland mixed dipterocarp forests throughout western Malesia and in the forests of New Guinea and Solomon Islands.

Phenology

Collected in flower June – Nov.; collected in fruit Jan. – Dec.

Vernacular

Ensarai (Iban, fide Coode et al. 7052); Kayu buluh/Kayu labu (Kedayan, fide Church et al. 14 & Puasa 7201); Merjawai (Iban, fide Coode et al. 6318); Mertama (Iban, fide Mohtar et al. S.47160 & S.47197, Haslinah et al. S.86696); OtoiPaseng (Punan, fide Coode et al. 7052); Pasil-pasil (Bajau Labuk, fide Apostol 7678); Sireh-sireh/Sirih-sirih (Iban, fide Hock S.46435, Munting & Jungah S.55601, Lai et al. S.75301, Tong S.34959, Julaihi et al. S.76946); Tanpahelaue (Merap, Persoon & Osseweijer 2008).

Use

Fruits edible (fide Apostol 7678, Coode et al. 6318 and Sundaling SAN 107497).