Classification of the Genus Mucuna

Notes and Caveats
The following is a hierarchy of taxonomic names showing the classification of the genus Mucuna.
I make no reference to the validity of the classification, but personally have found it to be very helpful.
Last update: February 3, 2014

Taxonomic Group Taxon Notes
Kingdom Plantae Plants
(unranked)      Angiosperms  
(unranked)           Eudicots
Subkingdom                Tracheobionta Vascular Plants
Superivision                     Spermatophyta Seed Plants
Division                          Magnoliophyta Flowering Plants
Class                               Magnoliopsida Dicotyledons
Subclass                                    Rosidae  
Order                                         Fabales  
Family                                              Fabaceae Lindl. (or Leguminosae Jussieu) Legume, Pea, or Bean Family
Subfamily                                                   Faboideae (or Papilionoideae Jussieu)  
Tribe                                                        Phaseoleae  
Genus                                                             Mucuna Adanson, 1763  

Characteristics of the genus Mucuna

Citation: Mucuna Adanson, 1763. Fam. Pl. 2: 325, 579. 1763
nom. cons. vs. Zoophthalmum P. Browne 1756, and vs. Stizolobium P. Browne 1756.

Explanation: Sometimes, a new taxonomic name is published by someone but is misspelled later on, by others. This mispelling becomes so commonly used that it would create havoc trying to get everyone to use the correct name; also, there are likely many records of the mispelled name in publications that would get "lost" if the correct spelling of a taxon was used. In such cases, the rules of nomenclature that state the original spelling of the "nomen" (i.e., the name) must be used are waived, by petition to a committee, and the commonly used mispelling is "conserved" or retained for use. This mispelling is then known as a nomen conservandum, or "nom. cons." for short.

Mucuna is a conserved name or nomen conservandum (nom. cons.). The original spelling was Macuna but because Mucuna had become so embedded in popular usage, it was conserved and officially designated as the valid spelling of the genus.

Type species: Mucuna urens (Linnaeus, 17__) de Candolle, 1825 typ. cons.

Explanation: The Author name(s) following a species name indicates who proposed that name; the date indicates when this was done in publication. Author's names are often abbreviated and thus you may see this species written as
"Mucuna urens (L) DC"
Because Linnaeus (or Linne) originally described the species urens in the genus Dolichos (i.e., as Dolichos urens), and this species has subsequently been transferred by botanists out of the genus Dolichos and into the genus Mucuna, the original author's name is placed into parenthesis. This change of generic placement was done by De Candolle.

A "type species" is that species chosen to represent what other species the genus Mucuna should contain. Species placed into this genus should generally conform to the caracteristics displayed by the type species. In the case of the genus Mucuna, the type species is Mucuna urens.

A "type specimen" (often used for the more definitive term, "holotype") is THE specimen, of the type species, that was used to describe the species and thus best exemplifies that species. There are many types of "type specimens", e.g., a "topotype" is any specimen collected from the "type locality"... i.e., where the holotype was collected. Type specimens are housed and cataloged in major museums supporting an extensive herbarium.

Number of valid/accepted Species: 100 to 150 species, plus or minus.
There are many nominal species of Mucuna (i.e., names of species) that are invalid species or are considered synonyms of accepted species.

Habit: Herbs, vines, rarely shrubs, climbing, woody, tall, rarely short and erect.
Note: this reference to "short and erect" MAY be referring to plants of Dioclea spp., misidentified as Mucuna

Distribution: Tropics of both North and South Hemispheres.

Leaves: pinnate 3-foliate, usually large; leaflets asymmetric, often oblique-ovate, indumentum (covering) usually hairy, aciculate (having a surface of fine lines as if scractced); bracts sometimes caducous (they fall off), stiples usually present; stipules small, usually caducous.

Flowers: large, showy, purple, orange, scarlet, red, or yellowish fascicled-racemose on axillary peduncles or subcymose at the apex of the peduncle; bracts and bracteoles small, caducous,; calyx often hairy, bilabiate; lobes 5 ovate, upper lip bilobed, lower lip trilled, longer; standard sessile, ovate-elliptic, folded inward eared at the base, ears often upturned. subequal to the wings; wings oblong-ovate, incurved, sessile, eared, often adherent to the keel; keel sessile, linear-oblong, incurved or beaked, often longer than and joined to the wings; stamens 10, diadelphous; anthers unequal, alternately longer and basifixed, shorter and dorsifixed, bearded; ovary sessile, few-ovules, villous, surrounded by a poorly developed, usually basal, cupular to lobular disk; style linear, filiform; stigma small, capitate (head-like, like head of a pin), terminal.

Pod (i.e., Fruit): thick, ovate to oblong, often covered with brown, stinging hairs, 2-valved, septate within.

Seeds: 1-10, large, rounded, discoid with hilum more or less one half the circumference or smaller ovoid, with a short, raised hilum.

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