Systellantha fruticosa (B.C.Stone) B.C.Stone

Drinkell, C. & Utteridge, T.M.A. 2015. A revision of the genus Systellantha B. C. Stone. Studies in Malaysian Myrsinaceae IV. Kew Bulletin 70: 50. DOI https://doi.org/10.1007/s12225-015-9603-8

Type

Type: Malaysia, Sarawak, Kapit Division, Balang/Balleh, Ulu Baleh [1°35'0""N 114°30'0""E], 5 July 1969, Paie S 28422 (holotype SAR n.v.; isotypes A n.v., E!, K!, L n.v., MEL n.v.).

Morphology General Habit

Shrub to c. 3 m

Morphology General Indumentum

Indumentum of minute, fuscous simple and ferruginous multi-cellular hairs with a sub-globose glandular apex, and elliptic to linear sessile glands

Morphology Branches

Branches slender, fawn, internodes ridged on each side, sparsely hairy with both hair types

Morphology Leaves

Leaves: blade lanceolate, 11 – 18 cm long, 1.5 – 4.2 cm wide, coriaceous, apex long attenuate, base acute, margins drying undulate, revolute; secondary venation obscure, 20 – 40 pairs; lamina ab- and adaxially sparsely sessile-glandular; petiole 4 – 15 mm long, sparsely hairy

Morphology Reproductive morphology Inflorescences

Inflorescences small, axillary; basal bracts 1 mm long, densely covered with multi-cellular hairs and sessile glands; pedicels 1 – 3 mm long (up to 4 mm long in fruit), sparsely covered with multi-cellular hairs with a sub-globose glandular apex

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens c. 3 mm long, c. 1 mm wide, filament c. 0.5 mm long, anthers lanceolate, connective caudate, drying ferruginous

Morphology Reproductive morphology Flowers

Pistillate flower: n.v. Staminate flowers: calyx lobes triangular, c. 1 mm long, apex acute, margins hyaline, hairy with multi-cellular hairs only, abaxially sessile-glandular; tubular corolla fused to 0.7 mm length, corolla lobes ovate, apex attenuate, c. 4 mm long, c. 2 mm wide, flesh-coloured (fideRichards 2388), ab- and adaxially sparsely sessile-glandular (multi-cellular hairs adaxially only from the base to the middle of the petal)

Morphology Reproductive morphology Fruits

Fruit sub-globose, apex very short acuminate, 7 – 10 mm long, 5 – 8 mm diam., fruit colour orange (fide Yii et al-S 52212), ripening medium blue (fide Anderson S 28372) to purplish (fide Paie 28422), densely sessile-glandular.

Distribution

Malaysia: endemic to Sarawak and only know from Kapit and Miri Divisions.

Ecology

Collected from primary dipterocarp forest; 500 – 1000 m above sea level.

Conservation

Systellantha fruticosa is given a preliminary assessment of Vulnerable VUB1ab (i, ii, iii). This taxon is only known from five collections from five locations, and both northern collections (Richards 2388 and Mohtar & Yii S 66206) are from areas that have been logged (apparent due to the network of logging roads from satellite imagery) but satellite imagery indicates that more southern collections from the Balleh river region are from areas that appear to have undergone less habitat conversion. Whilst AOO of 20 km2 falls within the Endangered threshold, we have used the EOO figure as a better indicator of population size partly because of the larger areas of extant habitat in the southern part of the species’ range. The EOO of 9,227 km2 falls within the Vulnerable threshold, and together with the number of locations (no more than 10), this threat category is proposed here.

Note

This species is very distinct on account of the comparatively thicker leaves, being the only member of the genus with coriaceous leaves, the entire leaf margins, and the fruit drying sub-globose with shorter fruiting pedicels (up to 4 mm long). All of the specimens have very narrow leaves (up to 23 mm wide), except for Richards 2388 which is slightly broader (42 mm wide) but falls within the range of variation in all other characters, and, in addition, is from a similar habitat in Sarawak. S. fruticosa has simple and multi-cellular hairs on the branches and petioles.