Trigonostemon laevigatus var. laevigatus

Yu, R. - Y. & Welzen, P. C. van, 2018, A taxonomic revision of Trigonostemon (Euphorbiaceae) in Malesia, Blumea 62 (3), pp. 179-229 : 197

1. Sepals without a gland outside....... a. var. laevigatus 1. Sepals with a gland outside............ b. var. croceus a. var. laevigatus — Fig. 5 ; Map 5

Sepals without a gland outside.

Distribution — As the species.

Habitat & Ecology — Mixed lowland dipterocarp forest, growing on clay to sandy soils to basalt derived soils of hill slopes. Altitude: 30–600 m. Flowering: all year round; fruiting: April, August, September, November.

Vernacular name — Borneo: Mampan (Banjar-Malay).

Notes — 1. The variety generally has a short petiole (often shorter than 1.5 cm) but it can be up to 4 cm long in some populations (e.g., in some populations from Brunei and Sabah). Since the variance is continuous, Airy Shaw’s var. petiolaris is synonymised here.

2. The sepals often have 2 layers of hairs on the outside, the relatively stiffer and longer hairs form the upper layer and often a layer of very dense and fine hairs that forms the lower layer and which is also present on the inside.

Figures

Fig. 5 Trigonostemon laevigatus Müll.Arg. var. laevigatus, from Kabili-Sepilok Forest Reserve, Sandakan, Sabah, Malaysia (a–e, g–h), and Kuala Belalong, Temburong, Brunei (f). a. Growing habit; b. leaves; c. reddish exude; d. bark and wood; e. staminate flower; f. pistillate flower; g. pistillate flower, petals fallen; h. fruit. — Photos by Ren-Yong Yu.