Olinia vanguerioides Baker f.

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

Type

Type: Zimbabwe, Gazaland, Umswirizwi head-waters, 1067 m, Swynnerton 158 (holotype BM! isotypes K!, PRE!).

Morphology General Habit

Shrubs or medium to large trees up to 10 m high

Morphology General Bark

Bark thin, grey, and finely reticulate branchlets quadrangular

Morphology Leaves

Leaves dark green on upper surface with pink-mauve tinge, light olive-green on under-surface, elliptic, coriaceous 36 – 73 × 24 – 40 mm margins inrolled Primary veins channelled above, light green Secondary veins distinctly visible on both surfaces, parallel to each other on each side of the midvein

Morphology Leaves Petiole

Petiole pink to red, pubescent, up to 4 mm long

Morphology Reproductive morphology Inflorescences

Inflorescence puberulent, spreading, light green and thin

Morphology Reproductive morphology Inflorescences Bracts

Bracts caducous, papery

Morphology Reproductive morphology Flowers

Flowers 5-merous, greenish to yellow, sweetly scented

Morphology Reproductive morphology Flowers Pedicel

Pedicels distinct, puberulent

Morphology Reproductive morphology Flowers Hypanthium

Hypanthium glabrous, narrow and thin-walled galled flowers show elongate wart-like tubercles

Morphology Reproductive morphology Flowers Calyx

Sepals as for the genus Petals 5, spathulate, short, narrow and thinly textured, yellowish, glabrous on both sides apex truncate

Morphology General Scales

Scales highly puberulent with soft hairs on both surfaces

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens as for the genus

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary inferior, 3- – 5-locular style puberulent, shorter than floral tube stigma globose

Morphology Reproductive morphology Fruits

Fruit globose, 5 – 7 mm in diam., whitish with circular scar at tip 2 – 4 mm wide.

Distribution

Known only from Zimbabwe (Map 7). It is widespread in central, south and eastern Zimbabwe. Although no records exist for Mozambique, it is highly probable that it occurs there given the similarity of habitats along the Zimbabwe/Mozambique border, especially along the Chimanimani mountain range.

Ecology

In crevices or among granite boulders/rocks near streams in kloof forests or on edge of relic forests solitary or often among Polysphaera, Erythroxylon, Hymenodictyon, Combretum, Ochna, Uvaria and lerodendrum evergreen thicket alt. 960 – 1200 m.

Conservation

The distribution of this species is limited to Zimbabwe where it is widespread (central, south and eastern parts and the highlands along the border with Mozambique). The number of collections in herbaria suggests great abundance in the areas of occurrence. Although there are no precise records of population numbers or information on possible habitat destruction, some labels indicate that the species is common where it was collected. Available evidence thus indicates that this species is not threatened and it is here assessed as of Least Concern (LC) under the IUCN Red List Categories.

Phenology

Flowers Dec. – Feb. fruits March – June.

Vernacular

Zimbabwean Olinia.

Note

Olinia vanguerioides exhibits a characteristic gall (flowers become twisted, grooved and bear numerous tubercles along elongated ridges) when flowers are infected by insect larvae compared to other species of Olinia that have their floral tubes swollen and smooth when infected (Sebola & Balkwill 2009). Having observed this condition, Verdcourt (1978) was convinced to keep O. vanguerioides as a distinct species separate from O. rochetiana. Olinia vanguerioides is often confused with O. rochetiana but can be distinguished by a distinct reticulate venation pattern on both surfaces of lamina, lateral vein pairs being 8 – 10 petal lobes that are spathulate, thinly textured and shorter than the hypanthium and a characteristic gall of the flowers.

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: low confidence

Oliniaceae, B. Verdcourt. Flora Zambesiaca 4. 1978

Note

Very closely allied indeed to the last species (Olinia rochetiana), differing in little but the petal size.

Morphology General Habit

Tree or shrub 2·4–25 m. tall; stems often shortly densely pubescent at apex, less often quite glabrous.

Morphology Leaves

Leaves 2·7–11·5 × 1·5–4·5 cm., very much as in previous species with characteristic dark pellucid venation against the glaucous pale under-surface, elliptic to elliptic-lanceolate, very often pubescent when young particularly on the midrib both above and below; petioles often red.

Morphology Reproductive morphology Flowers

Flowers in mostly dense many-flowered inflorescences, the peduncles branched and pedicels mostly densely shortly pubescent; bracts very small.

Morphology Reproductive morphology Flowers Calyx

Calyx-tube and combined receptacle 3–6 mm. long, more or less cylindrical, narrowed to the base, mostly pale, glabrous.

Morphology Reproductive morphology Flowers Corolla

Petals 1–1·5(2) mm. long, up to 0·5(1) mm. wide, yellow or white, mostly narrow, with a few hairs inside at base but scales densely pubescent so that the whole centre of the flower appears choked with hairs.

Morphology Reproductive morphology Fruits

Fruit 6 mm. in diameter, ?white, globose.