References

R.O. Moffett. 1994.
Rhus longispina and Rhus pterota, two hitherto confused South African shrubs,
South African Journal of Botany 60: 4 3-49. ISSN 0254-6299, https://doi.org/10.1016/S0254-6299(16)30659-7.

Abstract:
Rhus longispina Eckl. & Zeyh. and R. pterota Presl are two woody shrubs which are common in the eastern and southern Cape Province. Because of shared habitats and a superficial morphological similarity, these species have been regarded as conspecific and known as R. longispina for over one hundred and fifty years. A table showing the diagnostic characters separating the two species and a detailed description of each is given, followed by a list of selected specimens indicating their distribution.

Rhus longispina vs Rhus pterota
.* Drupe: Oblate, ellipsoid 3.5 X 2.3 - 6.8 X 4.7 mm, chestnut brown, drying dark brown; resinous juice and dry drupes astringent but palatable VS elliptic, ellipsoid 5.6 X 4.3 - 6.4 X 4.9 mm, slightly asymmetric, dark reddish brown, drying black; resinous juice and dry drupes pungent, distinctly unpalatable leaving a burning sensation in the mouth
.* Foliage - new growth: glabrous, shiny VS russet, glandular
.* Leaves: Petioles semiterete, occasionally margined; leaflets olive-green above, slightly paler below, often laccate; apex often emarginate VS petiole flattened, distinctly winged; leaflets dull grey-green above, slightly paler below, never laccate; apex never emarginate
.* Secondary veins impressed, not prominent VS prominent above, dull yellow, divided towards margin, often somewhat reversed
.* Habit: When mature - large rounded shrubs up to 4 m high VS somewhat untidy squarrose shrubs up to 2 m high
.* Panicles: Axillary and terminal, latter prominently exposed VS fasciculate, not prominently exposed
.* Bark: Pale grey-brown to dull yellowish on younger branches, granular to slightly striate VS fasciculate, not prominently exposed
.* Distribution: on diverse substrates near the coast and widespread in the Little and Great Karoo VS on calcareous substrates along the coast and adjacent interior.

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