Senna racemosa (Mill.) H.S.Irwin & Barneby var. racemosa
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Authors
Howard S. Irwin, Rupert C. Barneby
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Authority
Irwin, Howard S. & Barneby, Rupert C. 1982. The American Cassiinae. A synoptical revision of Leguminosae tribe Cassieae subtrib Cassiinae in the New World. Mem. New York Bot. Gard. 35, part 2: 455-918.
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Family
Caesalpiniaceae
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Scientific Name
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Type
Holotypus, labelled in Miller’s hand, BM! = NY Neg. 161 = Bailey Hort. Neg. 05169.
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Synonyms
Cassia racemosa Mill., Cassia ekmaniana Urb., Gaumerocassia ekmaniana (Urb.) Britton
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Description
Variety Description - Foliage strigulose-pilosulous, the leaf-hairs commonly subappressed, the lfts minutely puberulent or glabrous above; lvs (7-)9-17(-20) cm; lfts 4-8 pairs, the largest (2. l-)2.6-6 x (1-) 1.2-2.4(-2.7) cm, varying (sometimes on one plant) from elliptic or elliptic-oblanceolate subacute to obovate obtuse, the secondary veins 7-10 pairs from midrib, the mature blades reticulate on upper face; calyx relatively small, the outer sepals 2.3-3.5 mm, the glabrate inner ones 3.5-5.5 mm; 4 petals (9-) 10-14 mm, the odd petal (9-) 10.5-15.5 mm; anthers glabrous; ovary glabrous; style 1.3-2.2(-2.4) mm; body of pod 8-12 x 1-1.2(-1.5) cm.-Collections: 39. [Key: "Ovary and pod glabrous; mature lfts reticulately venulose on upper face; e. Mexico (s.-e. San Luis Potosi to Yucatan Peninsula), n.-e. Guatemala (Peten) and far w. Cuba; local in s.-w. Mexico (w. Michoacan and adjoining Colima). Lfts 4-8 pairs, their blades subappressed-pubescent, the upper face only minutely puberulent or glabrate; pod 8-12 cm, the seed-locules relatively narrow, 4-6 mm long; Yucatan Peninsula (Campeche to Quintana Roo) and adjacent Guatemala, w. to n. Oaxaca; far e. Cuba."]
Distribution and Ecology - Low hills and plains, in drought-deciduous brush savanna below 200 m, widespread over Yucatan Peninsula in e. Campeche, Yucatan and Quintana Roo (including Isla Cozumel), Mexico and n.-e. Guatemala (Peten), extending weakly w. into n. Oaxaca (distr. Tuxtepec) and localized on Guanahacabibes Peninsula across the Yucatan Channel in w. Pinar del Rio, Cuba.-Fl. I-III, VIII, the fr. long persisting after dehiscence.
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Discussion
The relatively widespread var. racemosa is characterized by thinly pubescent foliage that becomes reticulately venulose when mature, a glabrous brachystylous pistil, and a relatively short pod. The latter, however, is no fewer-seeded than the long pod of other varieties, but accommodates each seed in a narrower locule. The history of the name Cassia racemosa, which has only twice been associated correctly with a biological reality, has been clouded by vain efforts to apply Miller’s description to a plant native to northern Colombia. The name was as early as 1797 reduced by Martyn, in his revised edition of Miller’s Dictionary, to the synonymy of C. emarginata, but this was an error. The type-collection was examined by Vogel and briefly described in 1841 (Linnaea 15: 70) but not identified with any species recognized in Vogel’s revision of the genus (1837), where the name had been overlooked. Bentham (1870, p. 126; 1871, p. 549) revived C. racemosa for the taxon known to us as Senna silvestris which, while widely dispersed over much of forested tropical South America, has not been traced further northwestward than the Amazon-Orinoco divide in southeastern Colombia and the Maracaibo Basin in Venezuela. Britton & Killip (1936, p. 169) were unable to recognize Miller’s species in any Colombian cassia, and the supposed origin at Cartagena seems certainly to be mistaken, either due to a lapse of memory on Miller’s part or to mixture of materials at Chelsea. Miller’s plant (BM) was critically examined once again by Amshoff (1939, p. 23), who rejected Bentham’s interpretation but was unable to match it with any known species. In 1898 Pollard (in Millspaugh, Field Mus. Bot. 1: 366) had applied the name Cassia racemosa correctly to the arborescent senna of Yucatan Peninsula (Izamal, Gaumer 354; Merida, Schott 974), but without explanatory comment; his identification was accepted by Standley (1922, p. 411) but either overlooked or repudiated by Britton & Rose (1930). The attempt by Britton (sub Gaumerocassia) to distinguish between a larger-leaved G. ekmaniana from a smaller-leaved, sympatric G. peralteana is clearly ineffective even when applied to the specimens actually annotated by Britton himself, and involves a misinterpretation of genuine Cassia peralteana H.B.K., the earliest name for the species described in North American Flora as Pseudocassia anisopetala and Ps. petensis.
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Common Names
Yaax-haben
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Distribution
Campeche Mexico North America| Yucatán Mexico North America| Quintana Roo Mexico North America| Petén Guatemala Central America| Oaxaca Mexico North America| Piñar del Río Cuba South America|