Sterculia africana (Lour.) Fiori

First published in Agric. Colon. 5(Suppl.): 37 (1911 publ. 1912)
This species is accepted
The native range of this species is NE. Tropical Africa, Tanzania to Namibia, S. Arabian Peninsula. It is a tree and grows primarily in the seasonally dry tropical biome.

Descriptions

Sterculiaceae, Martin Cheek & Laurence Dorr; Nesogordonia, Laurence Dorr, Lisa Barnett. Flora of Tropical East Africa. 2007

Type
Type: Mozambique, Mossuril, Loureiro s.n. (P!, holo.)
Morphology General Habit
Tree 4–10(–18) m tall.
Morphology Bole
Bole often thick and squat, bark whitish grey or liver-colored; slash unknown; young extension shoots pale brown, shortly tomentellous
Morphology Leaves
Leaf-blade orbicular to ovate in outline, shallowly 3-lobed or entire, 3.5–10(–12.5) cm long, (3–)5–8(–11) cm wide, lateral lobes 0.5(–2) cm deep, always more shallow than the apical lobe, apex rounded to acuminate, base cordate, sinus 0.5–1.5 cm deep, edges usually not quite meeting, shortly and thinly tomentose to glabrescent above and beneath, hairs stellate, greyish with 5–7 ± horizontal arms; petiole 2.3–7.5(–12.5) cm long, 0.5 mm thick, tomentellous with greyish stellate hairs; stipules not long persistent
Morphology Reproductive morphology Inflorescences
Inflorescences borne on ± leafless stem apices, 2–6(–20) per shoot, 1.5–3 cm long, 1–2 cm wide, indumentum as the leaf, spike-like or branches 2–5; pedicels 3–8 mm long
Morphology Reproductive morphology Flowers
Flowers greenish or yellowish with pink or red markings, widely campanulate, 7–8 mm long, (5.5–)8–20 mm wide, divided into 5 rounded-triangular, patent or reflexed lobes 7–9 mm long, 4–4.5 mm wide, outside with small stellate hairs, as the leaf, inside glabrous apart from the lobes which densely covered in longer, white silky simple to 3–4-armed stellate hairs
Morphology Reproductive morphology Fruits
Fruits with follicles ± ellipsoid in lateral view, 6–11 cm long, widest at the equator in end view, 5–7 cm wide, dehiscing by 90–180°, then shorter and 8–9 cm wide, rostrum, if present, stout, slightly curved, 0–2 cm long, stipe stout and short if present, 0–0.5(–0.8) cm long, pericarp woody, 1.5–2(–4) mm thick, outer surface yellowish brown, tomentose to subscabrid, without sculpturing, inner surface yellowish white, softly and thinly tomentose, characteristically lined, placenta covered densely in yellow-brown urticating hairs 2–3 mm long.
Morphology Reproductive morphology Seeds
Seeds with peg-like stalks (2–)3–3.5 mm long, (0.5–)1–1.5 mm wide, covered with urticating hairs, persistently attached to the placenta. Seeds ellipsoid–oblong, grey-black, 12–15 mm long, 7–8 mm wide, the aril apical, 2–3 mm long, 3–5 mm wide, drying white; hilum at aril margin, round, 1–1.5 mm wide
Figures
Fig 1/1, 7, p 6
Ecology
Dry bushland or grassland with Combretum or Acacia, at the sea-shore in bushland with Sideroxylon and Xylocarpus, often on coral rock; 0–600 m
Conservation
This species is here assessed as “Least Concern” in view of its large geographic range and because of its wide habitat range.
Note
It is remarkable that though Sterculia africana is the only member of that genus illustrated in ‘Kenya Trees and Shrubs’, this species is not known from that country, though it is recorded to the North, from Ethiopia and Somalia, and to the South from Tanzania to South Africa and Botswana. Many specimens from Kenya which have initially borne the name Sterculia africana have subsequently proven to be the closely related S. rhynchocarpa (for diagnostic characteristics, see there). Both Greenway 5110 & 5289, figured in the K.T.S. plate, are from Mafia Island, Tanzania.   Sterculia triphaca var. rivaei was very probably based on specimens attributable to both Sterculia africana and to S. rhynchocarpa. This is because two of the six syntypes of var. rivaei (both believed destroyed) were from Kenya, whence specimens of S. africana are unknown, although S. rhynchocarpa is common. Sterculia arabica (R.Br.) T.Anders of Yemen and Oman is very closely related to Sterculia africana. Specimens of the former can usually be differentiated by the smaller, uniformly rounded leaves and smaller fruits, about half the size of the latter. However, qualitative differential characters seem scarce and monographic research might relegate these two taxa to subspecific rank. Sterculia arabica has nomenclatural priority. Specimens collected from coastal districts at sea-level, including all those from Mafia and Zanzibar, have very much larger and more sparsely hairy leaves than those from Acacia bushland, but this phenomenon may be environmentally engendered. Although several varieties have been recognized throughout the coastal range of Sterculia africana, examination of the available material from E Africa suggests that these are unwarranted. Although the species does seem rather variable in leaf-shape and indumentum, intermediates can be demonstrated. The record from T 8 is derived from a sight record at Ngarama North Forest Reserve by Luke (pers. comm.).
Distribution
Flora districts: T3 T5 T6 T7 T8; Z Range: Sudan, Ethiopia, Somalia, Angola, Zambia, Malawi, Mozambique, Zimbabwe
[FTEA]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Tree, up to 10 m tall or more, with a thick trunk; bark peeling in papery flakes; branchlets puberulous to tomentose
Morphology Leaves
Leaves crowded at ends of branches, ± densely pubescent; petiole up to 10 cm long; blade 5–15 x 4–13 cm, broadly ovate-cordate, deeply 3–5(–7)-lobed with ± acuminate lobes or rarely entire
Morphology Reproductive morphology Inflorescences
Flowers in narrow 3–12 cm long pubescent panicles
Morphology Reproductive morphology Flowers Calyx
Calyx up to 12 mm long, reddish with yellowish-green lobes, pubescent outside
Morphology Reproductive morphology Flowers
Male flowers with androphore up to 10 mm long Female flowers with gynophore up to 7 mm long
Morphology Reproductive morphology Fruits
Follicles 4–10 cm long, oblong-ovoid, thick-walled, longitudinally ribbed, tomentose with short yellowish hairs, with a horn-like beak up to 1 cm long at the apex, opening up partly only
Morphology Reproductive morphology Seeds
Seeds 9–11 x 5–6 mm, dull black.
Distribution
N1 from S Tanzania southwards to Namibia and Botswana.
Ecology
Altitude range 1050–1380 m.
Vernacular
Garaho, qararro (Somali).
[FSOM]

Sterculiaceae, H. Wild. Flora Zambesiaca 1:2. 1961

Morphology General Habit
Tree 10–25 m. tall, with a stout trunk up to 1 m. in diam. somewhat resembling that of the Baobab; bark peeling in papery flakes, brownish, yellowish, whitish or liver-coloured, inner layers green and with the sapwood pink; primary branches stiff and very stout.
Morphology Leaves
Leaf-lamina 5–15 × 4–13 cm., very broadly ovate-cordate, apex acuminate, almost entire or 3–5-lobed with somewhat acuminate lobes, c. 7 nerved at the base, from thinly to densely and harshly pubescent or tomentose, sometimes glabrescent; petiole up to 10 cm. long, coarsely pubescent. Leaves collected at the ends of the branches.
Morphology Reproductive morphology Flowers
Flowers in clustered, usually terminal panicles appearing before the leaves and up to 9 cm. long; branches of inflorescence densely pubescent; bracteoles c. 1·5 mm. long, linear-oblong, acute, pubescent; pedicels up to 1 cm. long, articulated near the middle, pubescent. Female flower: ovary ovoid, tomentose, with a few vestigial stamens at its base, on a puberulous gynophore c. 4 mm. long; style c. 3 mm. long, pubescent, often reflexed. Male flower: stamens c. 10, in a capitate discoid cluster; androphore 5–6 mm. long, slender, glabrous.
Morphology Reproductive morphology Flowers Calyx
Calyx up to 1·2 cm. long, yellowish with reddish guide-lines within, campanulate, divided rather more than half way into 5–6 acute lobes, tomentellous outside, glabrous within except near the apex.
sex Male
Male flower: stamens c. 10, in a capitate discoid cluster; androphore 5–6 mm. long, slender, glabrous.
sex Female
Female flower: ovary ovoid, tomentose, with a few vestigial stamens at its base, on a puberulous gynophore c. 4 mm. long; style c. 3 mm. long, pubescent, often reflexed.
Morphology Reproductive morphology Fruits
Follicles 3–5, c. 10 cm. long, spreading, subsessile, oblong-ovoid, with a horn-like often curled apiculus at the apex, golden-tomentellous and finely longitudinally ridged outside, opening widely after dehiscence; placentas with very dense acicular hairs.
Morphology Reproductive morphology Seeds
Seeds numerous, c. 2 × 1 cm., oblong-ellipsoid, with a whitish aril at one end; testa smooth, dull-blackish.
[FZ]

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/62754/146209124

Conservation
LC - least concern
[IUCN]

Uses

Use
Bark used for rope, Greenway 5110.
[FTEA]

Sources

  • Art and Illustrations in Digifolia

    • Digital Image © Board of Trustees, RBG Kew
  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • IUCN Categories

    • IUCN Red List of Threatened Species
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0