Tolumnia Raf.

First published in Fl. Tellur. 2: 101 (1837)
This genus is accepted
The native range of this genus is Mexico to N. South America, Florida to Caribbean.

Descriptions

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit
Mostly small twig epiphytes, rarely lithophytic or terrestrial, with short or long and wiry rhizomes
Morphology Stem
Stems small, usually completely hidden by leaf bases, sometimes pseudobulbous
Morphology Leaves
Leaves articulate, fan-like arrangement, fleshy coriaceous, conduplicate, laterally compressed or subterete, psygmoid (incorrectly referred to as “equitant”)
Morphology Reproductive morphology Inflorescences
Inflorescences lateral from between leaf bases, pedunculate, racemose or paniculate, few–many-flowered
Morphology Reproductive morphology Flowers
Flowers generally colorful, showy, resupinate; dorsal sepal free, erect, lateral sepals free or variously connate; petals free, spreading, usually larger than the dorsal sepal; lip attached to the base of the column, nectary absent, trilobed, midlobe usually emarginate, disc callus absent to tuberculate, glabrous to pubescent
Morphology Reproductive morphology Flowers Column
Column erect, semiterete, footless, subapical lateral wings flanking the stigma footless, tabula infrastigmatica present
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anther terminal, operculate, incumbent, pollinia 2, hard, waxy, attached to an elongate stipe with a small viscidium
Morphology Reproductive morphology Fruits
Capsules ellipsoidal.
Distribution
A genus of 25 species, some not well-defined. Most species occur in the Greater Antilles, but some are known from the United States (southern Florida), the Bahamas and the Lesser Antilles.
Recognition
Popularly known as the “variegata” or “equitant” group of oncidiums, Tolumnia is vegetatively distinct from Oncidium but the flowers are very similar, probably owing to evolutionary convergence. Vegetative morphology, chromosome numbers and molecular sequence data are all congruent and support the segregation of Tolumnia from Oncidium.
[Cayman]

Sources

  • Flora of the Cayman Islands

    • Flora of the Cayman Islands
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • 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