Stathmostelma K.Schum.

First published in Bot. Jahrb. Syst. 17: 129 (1893)
This genus is accepted
The native range of this genus is Cameroon to Ethiopia and Botswana.

Descriptions

Goyder, D. J., Gilbert, M. G. & Venter, H. J. T. (2020). Apocynaceae (part 2). In: M. A. García (ed.), Flora Zambesiaca, Vol. 7(3). Royal Botanic Gardens, Kew.

Morphology General Habit
Perennial herbs with annual stems arising from a slender to stout vertical tuber; latex milky
Morphology Stem
Stems 1 to many, simple or branched, erect or ascending, glabrous or minutely pubescent with short, spreading hairs
Morphology Leaves
Leaves opposite, sessile or petiolate; lamina linear to ovate, both upper and lower surfaces pubescent with spreading white hairs or indumentum restricted to margins and midrib below
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, extra-axillary or both, umbels erect, borne on long or short peduncles
Morphology Reproductive morphology Flowers Calyx
Calyx lobes to the base
Morphology Reproductive morphology Flowers Corolla
Corolla rotate to strongly reflexed, occasionally broadly campanulate
Morphology Reproductive morphology Flowers Corona
Corolline corona absent
Morphology Reproductive morphology Flowers Gynostegium
Gynostegium sessile or with stipe to 3 mm long Gynostegial corona of 5 lobes arising above the base of the staminal column; erect and somewhat fleshy, frequently weakly pouched towards the base and concave-cucullate for at least some of its length, the inner apical margins generally produced into a pair of inward- or upward-pointing teeth, with or without a tooth arising from the middle of the cavity, glabrous except along the midline of the cavity towards the base of the lobe
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anther wings curved, with or without a contorted basal tail
Morphology Reproductive morphology Flowers Pollinarium
Corpusculum ovoid to subcylindrical or occasionally subglobose, black; translator arms with a membranous, convex and somewhat contorted proximal portion, and a filiform distal portion broadening abruptly into a short clasping overlap with the pollinium; pollinia flattened, oblong
Morphology Reproductive morphology Flowers Gynoecium Style
Stylar head flat
Morphology Reproductive morphology Fruits
Fruiting pedicel not contorted; follicles single, erect, ovoid to fusiform, beaked, occasionally inflated but generally not, smooth or with weak longitudinal ridges, glabrous to densely pubescent
Morphology Reproductive morphology Seeds
Seeds ovate with a verrucose disc and a narrow inflated rim; coma of silky hairs.
Distribution
Distributed mostly in eastern parts of tropical Africa, growing mostly at middle altitudes from Ethiopia in the north to Mozambique and Zimbabwe in the south.
Recognition
Very closely allied to Margaretta.
[FZ]

Apocynaceae (part 2), David Goyder, Timothy Harris, Siro Masinde, Ulrich Meve, Johan Venter. Flora of Tropical East Africa, 2012

Morphology General Habit
Perennial herbs with annual stems arising from a slender to stout vertical tuber.
Morphology General Exudate
Latex milky.
Morphology Stem
Stems 1 to many, simple or branched, erect or ascending, glabrous or pubescent with short, spreading hairs
Morphology Leaves
Leaves opposite, sessile or petiolate
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, extra-axillary or both, umbels erect, borne on long or short peduncles
Morphology Reproductive morphology Flowers Calyx
Calyx lobed to the base
Morphology Reproductive morphology Flowers Corolla
Corolla rotate to strongly reflexed, occasionally broadly campanulate
Morphology Reproductive morphology Flowers Corona
Corolline corona absent Gynostegial corona of 5 lobes arising above the base of the staminal column; erect and somewhat fleshy, frequently weakly pouched towards the base and concave-cucullate for at least some of its length, the inner apical margins generally produced into a pair of inward- or upward-pointing teeth, with or without a tooth arising from the middle of the cavity, glabrous except along the midline of the cavity towards the base of the lobe
Morphology Reproductive morphology Flowers Gynostegium
Gynostegium sessile or with stipe to 3 mm long
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anther wings curved, with or without a contorted basal tail
Morphology Reproductive morphology Flowers Pollinia
Corpusculum ovoid to subcylindrical or occasionally subglobose, black; translator arms with a membranous, convex and somewhat contorted proximal part, and a filiform distal part broadening abruptly into a short clasping overlap with the pollinium. Pollinia flattened, oblong, pendant in the anther cells
Morphology Reproductive morphology Flowers Gynoecium Style
Stylar head flat
Morphology Reproductive morphology Flowers Pedicel
Fruiting pedicel not contorted.
Morphology Reproductive morphology Fruits
Follicles single, erect, ovoid to fusiform, beaked, occasionally inflated but generally not, smooth or with weak longitudinal ridges, glabrous to densely pubescent
Morphology Reproductive morphology Seeds
Seeds flattened, ovate, with a verrucose disc and a narrow inflated rim; coma of silky hairs.
[FTEA]

Sources

  • Flora Zambesiaca

    • Flora Zambesiaca
    • 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

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 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 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0