Senna pendula |
Senna obtusifolia |
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climbing cassia, valamuerto |
blunt leafed senna, Chinese senna, Java-bean, sickle-pod wild senna, sicklepod |
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Habit | Herbs, annual or biennial, to 1.2(–2.4) m. Leaves mesophyllous, 3.5–17 cm, pallid green, slightly and finely hairy or glabrous; stipules caducous; extrafloral nectary 1, usually between first leaflet pair, rarely also between second, sessile or shortly stipitate; leaflet pairs 3, blades obovate to cuneate-obovate or broadly cuneate-oblanceolate, 17–65 × 10–40 mm. | |
Racemes | usually 1 or 2(or 3)-flowered; bracts caducous. |
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Pedicels | 7–28 mm. |
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Flowers | asymmetric, enantiostylous; calyx pale green; corolla pale yellow, longest petal 9–15 mm, 1 lower petal conspicuously larger; androecium heterantherous, stamens 7, middle stamens 1/2 as long as abaxial or smaller, staminodes 3; anthers of middle stamens 1–2.8 mm, of abaxial stamens 2–5 mm, dehiscing by U-shaped slit, apical appendage inconspicuous, cupped; gynoecium incurved, ovules 16–38; ovary hairy; style incurved. |
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Legumes | erect or curved downward, flat, straight, 60–180 × 2.5–6 mm, faintly corrugated over seeds, indehiscent. |
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Seeds | dark reddish brown, rhomboid or subcylindroid-oblong. |
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Senna | pendula is often confused with close relative S. bicapsularis, which is absent from North America and has shorter pedicels, only to 5 mm (H. |
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s | . Irwin and R. |
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c | . |
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Barneby | 1982; B. |
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Marazzi | et al. |
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2006b | ). |
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2n | = 24, 26, 28. |
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Senna pendula |
Senna obtusifolia |
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Phenology | Flowering late spring–mid winter. | |
Habitat | Lakeshores, riverbanks, river beds, disturbed habitats, pastures, plantations, orchards, roadsides, waste places. | |
Elevation | 0–1700 m. (0–5600 ft.) | |
Distribution |
Mexico; Central America; South America; West Indies [Introduced, Florida; introduced also in Africa (South Africa), Pacific Islands, Australia]
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AL; AR; CA; FL; GA; IL; IN; KS; KY; LA; MA; MD; MO; MS; NC; NJ; NY; OK; PA; SC; TN; TX; VA; WV [Introduced in Asia, Africa, Atlantic Islands, Indian Ocean Islands, Pacific Islands, Australia]
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Discussion | Varieties 18–20 (1 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Senna obtusifolia is one of the most widespread weedy sennas native to the Americas (H. S. Irwin and R. C. Barneby 1982) and is probably naturalized circumtropically. The species is considered a noxious weed in many countries, posing problems especially for agriculture; it is able to completely invade pastures by dominating grass species, it strongly competes with crops, affecting yields negatively, and, although generally unpalatable to stock, if eaten, it is toxic to cattle. For these reasons, in Australia S. obtusifolia is designated as potentially of national concern, and authorities estimate that this invader can lead properties to become unproductive (Weeds of Australia, www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weedsearch.pl; Land Protection, www.nrw.qld.gov.au/factsheets/pdf/pest/pp18.pdf). In the flora area, its range of distribution appears to have expanded from five southern and southeastern states in the early 1980s (Florida, Kentucky, Missouri, Texas, and Virginia; Irwin and Barneby) to currently almost half of the states. Although a few specimens were collected as far north as Nebraska and Wisconsin, it is not known to be established in those states. Senna tora (Linnaeus) Roxburgh (Cassia tora Linnaeus) is sometimes considered synonymous with S. obtusifolia. However, due to differences in length and curvature of the fruit and in length of the petiole and pedicel, B. R. Randell and B. A. Barlow (1998) considered it distinct. H. S. Irwin and R. C. Barneby (1982) observed a range rather than distinct categories in the measures and shapes of these traits, and only molecular phylogenetic and biogeographic studies accompanied by morphometric analyses may definitively solve this taxonomic dilemma. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | Fabaceae > subfam. Caesalpinioideae (excluding Mimosoid clade) > Senna | Fabaceae > subfam. Caesalpinioideae (excluding Mimosoid clade) > Senna |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Cassia pendula, Chamaefistula pendula | Cassia obtusifolia, C. tora var. humilis, C. tora var. obtusifolia, C. toroides |
Name authority | (Humboldt & Bonpland ex Willdenow) H. S. Irwin & Barneby: Mem. New York Bot. Gard. 35: 378. (1982) | (Linnaeus) H. S. Irwin & Barneby: Mem. New York Bot. Gard. 35: 252. (1982) |
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