e-Key v3 - Androstachys
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.

Euphorbiaceae - Oldfieldioideae - Picrodendreae - Androstachys Prain

Description :

  • Trees, dioecious; rather rigid, even branchlets, decussately branched; branchlets adpressed silky-pilose, angled, articulated
  • Leaves decussate, petiolate, ovate to suborbicular, usually subcordate, densely silky on undersurface; stipules large, connate, sheathing, deciduous
  • Flowers axillary; male inflorescence a shortly pedunculate triad of cernuous, catkin-like spikes or racemes; female flowers solitary
  • Petals 0
  • Disc 0
  • Male flowers : calyx of 2-5 bract-like, spirally arranged, ciliate sepals; stamens many, spirally arranged on prolonged axis, with lowest filaments short and recurved, upper subsessile; anthers with thecae slightly divided and with few, long hairs at apex; pistil absent
  • Female flowers : calyx 5-partite, with ovate-acuminate, imbricate segments; ovary 3- or 4-locular, with 2 ovules in each locule; densely tomentose; styles connate into a pilose column; stigmas 3, spreading, large, linear-lanceolate
  • Fruit breaking up into 3 or 4 bivalved cocci, depressed-globose, often with dense indumentum
  • Seeds elliptic-globose; testa hard and shiny; embryo straight with two collateral rounded cotyledons, chlorophyllous; endosperm abundant, oily

Nomenclature:

  • Androstachys Prain
    • Prain: 438 (1908)
    • Hutchinson: 377 (1915)
    • Airy Shaw: 251 (1965) Androstachydaceae Airy Shaw
    • Airy Shaw: 519 (1970)
    • Leroy: 147 (1976)
    • Alvin: 579 (1987)
    • Dahlgren & Van Wyk: 3 (1988) Androstachydaceae
    • Webster: 61 (1994)
    • Radcliffe-Smith: 120 (1996)

Distribution & Notes:

  • Global : Species 1: Androstachys johnsonii Prain, Africa and Madagascar
  • Southern Africa : Northern Province, Mpumalanga and Swaziland

References:

  • AIRY SHAW, H.K. 1965. Diagnoses of new families, new names, etc. for the seventh edition of Willis's 'Dictionary'. Kew Bulletin 18
  • AIRY SHAW, H.K. 1970. The genus Androstachys Prain in Madagascar. Adansonia , ser. 2, 10
  • ALVIN, K.L. 1987. Leaf anatomy of Androstachys johnsonii Prain and its functional significance. Annals of Botany (London) 59
  • DAHLGREN, R. & VAN WYK, A.E. 1988. Structures and relationships of families endemic to or centered in southern Africa. Monographs in Systematic Botany from the Missouri Botanical Garden 25
  • HUTCHINSON, J. 1915. Euphorbiaceae [in part]. Flora capensis 5, 2
  • LEROY, J.-F. 1976. Recherches sur la nature et l'origine de la fleur angiospermiene: interprétation des structures dans un groupe singulier d'Euphorbiaceae. Compte Rendu Hebdomadaire des séances de l'Académie des Sciences , sér. D. 283
  • PRAIN, D. 1908. Androstachys Prain, gen. nov. In Diagnoses Africanae: XXVI. Bulletin of Miscellaneous Information, Kew 1908
  • RADCLIFFE-SMITH, A. 1996. Euphorbiaceae . Flora zambesiaca 9, 4
  • WEBSTER, G.L. 1994. Synopsis of the genera and suprageneric taxa of Euphorbiaceae . Annals of the Missouri Botanical Garden 81