Fabaceae
Exostyles

Exostyles amazonica Yakovlev

First published in Novosti Sist. Vyssh. Rast. 16: 138 (1979)
This species is accepted
The native range of this species is Suriname to N. Brazil. It is a tree and grows primarily in the wet tropical biome.

Descriptions

Vidal de Freitas Mansano, & Lewis, G. (2004). A Revision of the Genus Exostyles Schott (Leguminosae: Papilionoideae). Kew Bulletin, 59(4), 521-529. doi:10.2307/4110906

Type
Brazil, Amazonas, Rio Jari, Monte Dourado, N. T Silva 1372 (holotype NY., isotypes NY., RB!).
Morphology General Habit
Tree 20 - 25 m
Morphology Leaves Stipules
Stipules 4.9 x 0.6 mm, linear, pilose; leaves imparipinnately 7 - 11-foliolate; petiole 4.5 mm long, canaliculate, densely pilose; rachis c. 8 cm long, canaliculate, densely pilose; stipels c. 2 x 0.3 mm, oblong; petiolules 1.2 mm long, densely pilose; lateral leaflets c. 3.7 x 2.5 cm, ovate, the terminal one larger than the others, adaxial surface sparsely pilose on the midvein, abaxial surface pilose on the midvein, margin obscurely dentate, base oblique, apex acuminate, midvein prominent abaxially, blade concolorous
Morphology Reproductive morphology Inflorescences
Raceme c. 2.5 cm long, axillary, axis densely pilose; bracts c. 5.8 x 1.3 mm, triangular, ciliate; bracteoles c. 2.3 x 0.8 mm, triangular, ciliate, attached half way up the pedicel; pedicel c. 8 mm long, densely pilose
Morphology Reproductive morphology Flowers
Flower with hypanthium c. 5.3 mm deep; calyx 2-lobed at anthesis, brownish, glabrous internally; petals not seen, cream (from field label data); stamens 10, filaments c. 7.8 x 0.2- 0.4 mm, glabrous, anthers c. 2.1 x 1.1 mm, ovate with apiculate apex, glabrous; stipe c. 9.3 mm long, sparsely pilose, ovary c. 9 x 2 mm, oblong, sericeous, style c. 7.7 mm long, straight, terminal, glabrous, stigma capitate
Morphology Reproductive morphology Fruits
Fruit 18.2 x 3.1 cm, indehiscent, brownish when dried, glabrous externally, c. 6-seeded.
Distribution
Brazilian Amazon and Surinam
Ecology
Exostyles amazonica grows on sandy soil in the Amazon forest and in high hill forest on granite and laterite in Suriname (the latter a newly recorded geographical range extension).
Phenology
Flowering in October and fruiting in March.
Note
Exostyles amazonica differs from all other species in having a sericeous (vs. glabrous) ovary and stamen filaments over 7 mm long (vs. under 5 mm long). It is the only species occurring in the Amazon.
[KBu]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: low confidence
[AERP]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • Herbarium Catalogue Specimens

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

  • Kew Bulletin

    • Kew Bulletin
    • http://creativecommons.org/licenses/by-nc-sa/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

  • World Checklist of Vascular plants (WCVP)

    • 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