Olinia micrantha Decne.

Sebola, R.J. & Balkwill, K. 2013. A monographic study of the Oliniaceae. Kew Bulletin 68: 419. https://doi.org/10.1007/s12225-013-9465-x

Morphology General Habit

A large tree up to 15 m high

Morphology General Bark

Bark pale to dark grey and rectangularly fissured or reddish brown and flaking, trunk often fluted branchlets slightly velvety

Morphology Leaves

Leaves concolorous, broadly elliptic to obovate, 20 – 30 × 10 – 11 mm, leathery, more or less the same colour on both surfaces apex obtuse to apiculate, slightly mucronate base attenuate or tapering margin entire Midvein or primary veins level with lamina Secondary veins inconspicuous above and below

Morphology Leaves Petiole

Petiole (1 –) 1.5 – 2.8 (− 3) mm long, slightly pubescent on dorsal surface

Morphology Leaves Stipules

Stipules as for the genus

Morphology Reproductive morphology Inflorescences

Inflorescence axillary and terminal, compact, dichasial cymes

Morphology Reproductive morphology Inflorescences Peduncles

Peduncle pubescent, (1.8 –) 2 – 3.5 (− 3.8) mm long

Morphology Reproductive morphology Inflorescences Bracts

Bracts subulate, pubescent on both surfaces, (5 –) 7 – 9 (− 12) × (2.5 –) 5 – 5.5 (− 6.5) mm, cream-white, persistent or falling shortly after the flowers open (anthesis) (August – January)

Morphology Reproductive morphology Flowers

Flowers very small, whitish, sometimes tinged with pink, in dense axillary heads, 50 – 60 mm long, sweetly scented pedicel glaucous, short

Morphology Reproductive morphology Flowers Hypanthium

Hypanthium glabrous, (1.5 –) 2 – 2.5 (− 3) mm long

Morphology Reproductive morphology Flowers Calyx

Sepals as for the genus

Morphology Reproductive morphology Flowers Corolla

Petals glabrous on outer surface, inner surface with tuft of short hairs at base, (1 –) 1.2 – 1.8 (− 2) × (0.5 –) 0.7 – 0.8 (− 1) mm

Morphology General Scales

Scales incurved, highly pubescent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 5, as for the genus

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 3- – 5-locular style glabrous, shorter than floral tube stigma globular

Morphology Reproductive morphology Fruits

Fruit globose, about 10 mm in diam., soft and thinly fleshy, red, visible circular scar at the apex on young fruit, disappearing in mature fruit (Dec./Jan – June).

Distribution

The species is known only from the Eastern Cape, South Africa, mainly in the transitional zone receiving both winter and summer rainfall.

Ecology

Occurs in evergreen forests, at forest margins and along ravines alt. 950 – 1950 m.

Conservation

This species has a narrow distribution range in the Eastern Cape region of South Africa. It was placed in a preliminary list of tree species for assessment for protection under the National Forest Act (Department of Water Affairs and Forestry, Act no. 84 of 1998) of South Africa but was omitted from the final list after evaluation that combined information on Red List status, keystone species in sensitive and tree dominated ecosystems, sustainability of use, cultural and spiritual value, and other applicable legislative provisions. The decision rule applied was to eliminate this species from the list of protected tree species because ‘the species does not have significant ecological, commercial or cultural value and does not face any significant threat, and is well protected by legislation (National Forest Act)’. Based on this assessment and that this species is abundant where it occurs, it is assigned the IUCN Red Data status of Least Concern (LC).

Note

This species is sympatric with Olinia capensis and O. ventosa. With regard to variation in leaf dimensions, O. micrantha overlaps with O. emarginata while the retention of bracts after anthesis makes O. micrantha similar to O. capensis from which it differs by the shape (subulate vs linear to elliptic) and length of bracts (shorter than 8.5 mm). The flowering periods also distinguish O. micrantha (Aug. – Jan.) from O. capensis (May – July). This species is similar to Olinia emagrinata but differs by its shorter leaves (23 – 37 mm vs 36 – 71 mm long), and the retention of bracts after anthesis, which makes it more similar to O. capensis.

Type

Type: South Africa, Mpumalanga, near Barberton, Upper Moodies at 3300 ft, Galpin 1275 (holotype J! isotypes K!, PRE!). Type: Afr. Austr. Cat. Geogr. Plant Extratrop., Burchell 3592 (holotype K!).