Apocynaceae

Holarrhena R.Br.

First published in Asclepiadeae: 51 (1810)
This genus is accepted
The native range of this genus is Tropical & S. Africa, Indian Subcontinent to Peninsula Malaysia.

Descriptions

Apocynaceae, A. J. M. Leeuwenberg & F. K. Kupicha et al. Flora Zambesiaca 7:2. 1985

Morphology General Habit
Deciduous shrubs or trees with white latex and unarmed branches.
Morphology Leaves
Leaves opposite or subopposite, those of a pair equal, shortly petiolate, without colleters in the axils; petiole glandular near the base.
Morphology Leaves Stipules
Stipules intrapetiolate and often obscure or absent.
Morphology Reproductive morphology Inflorescences
Inflorescences terminal and/or apparently axillary, cymose, many-flowered.
Morphology Reproductive morphology Flowers
Flowers sweet-scented, actinomorphic or with sepals only unequal.
Morphology Reproductive morphology Flowers Calyx
Sepals free or connate at the very base, subequal or sometimes unequal, with colleters inside at the base and alternating with the sepals.
Morphology Reproductive morphology Flowers Corolla
Corolla hypocrateriform; tube cylindrical, slender, wider near the base and apex; lobes contorted in bud and overlapping to the right.
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens included, inserted at the base of the corolla-tube; anthers glabrous, basifixed, rounded at the base, mucronate at the apex.
Morphology Reproductive morphology Flowers Gynoecium Pistil
Ovary superior, carpels 2, connate at the very base only, ovoid, gradually narrowed into the style; disk none; style cylindrical; clavuncula ovoid; stigma bifid; placentas adaxial; ovules numerous.
Morphology Reproductive morphology Fruits
Fruit composed of 2 scarcely diverging mericarps; mericarps follicular, slender, more or less constricted between the seeds.
Morphology Reproductive morphology Seeds
Seeds numerous, linear to very narrowly oblong, striate, grooved, glabrous, with a dense tuft of hairs at the apex; embryo large, surrounded by the very scanty endosperm.
[FZ]

Apocynaceae, E.A. Omino. Flora of Tropical East Africa. 2002

Morphology General Habit
Deciduous shrubs or trees up to 25 m high, with abundant white latex in all parts
Morphology Leaves
Leaves (sub-)opposite, petiole glandular near the base
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, cymose, many-flowered; bracts without colleters
Morphology Reproductive morphology Flowers
Flowers fragrant
Morphology Reproductive morphology Flowers Calyx
Sepals persistent, valvate, with 0–10 colleters at the base
Morphology Reproductive morphology Flowers Corolla
Corolla salver-shaped; tube cylindrical, pubescent at the throat; lobes white, overlapping to the right
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens inserted at the base of the corolla tube; filaments short, pubescent at the base
Morphology Reproductive morphology Flowers Gynoecium Pistil
Pistil glabrous or pubescent; disk absent; ovary ovoid, of two carpels, connate at the extreme base, placentas adaxial; ovules numerous, in 4–8 rows; pistil head ovoid; stigmoid apex bifid
Morphology Reproductive morphology Fruits
Fruit of two thin-walled slender follicles, dehiscent; seeds glabrous, with a dense tuft of hairs at the apex, 3–6×as long as the seeds; embryo large, with a scanty endosperm; cotyledons large, complicate.
[FTEA]

Common Names

unknown
mai muk noy (Lao)

Sources

  • EBC Common Names

    • Common Names from Kew's Economic Botany Collection https://www.kew.org/science/collections-and-resources/collections/economic-botany-collection

  • 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

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2026. 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 2026. 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