Senna roemeriana |
Senna covesii |
|
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Roemer senna, twoleaf senna, twoleaf wild sensitive plant |
Coues' cassia, Coves' cassia, desert senna |
|
Habit | Herbs, perennial, to 0.7 m. Leaves slightly sclerophyllous, 2.5–9.5 cm, hairy; stipules caducous; extrafloral nectary 1, between leaflet pair, shortly stipitate; leaflet pairs 1, blades lanceolate-oblong or lanceolate, 20–70 × 4–14 mm. | Herbs, perennial, to 0.7 m. Leaves slightly sclerophyllous, 2–10 cm, hairy; stipules persistent, to 1 mm wide; extrafloral nectaries between all leaflet pairs, stipitate; leaflet pairs 2–4, blades obovate to elliptic-obovate or oblong-elliptic, 10–38 × 5–19 mm. |
Racemes | 1–5-flowered; bracts caducous. |
(2–)4–8-flowered; bracts caducous. |
Pedicels | 9–16 mm. |
8–17 mm. |
Flowers | monosymmetric; calyx caducous, pale green; corolla yellow or orange-yellow, longest petal 12–17 mm; androecium not heterantherous, stamens 7, staminodes 3; anthers 2.2–3.3 mm, dehiscing by 1 apical pore, apical appendage 0; gynoecium nearly linear, ovules 22–40; ovary densely hairy; style slightly incurved. |
monosymmetric; calyx pale green, pinkish, or yellowish; corolla golden yellow, longest petal 9–15 mm; androecium not heterantherous, stamens 7, staminodes 3; anthers 2.5–4.2 mm, dehiscing by 1 apical pore, apical appendage 0; gynoecium linear, slightly incurved, ovules 28–42; ovary hairy; style filiform, incurved. |
Legumes | erect, subcylindrical, straight or slightly curved, 20–35 × 4.5–6.5 mm, corrugated over seeds, dehiscing apically downward. |
erect, cylindrical, slightly curved, 180–350 × 50–80 mm, shallowly corrugated over seeds, dehiscing apically downward. |
Seeds | brown or pinkish brown, paddle-shaped or pyriform. |
brown, rhomboid. |
2n | = 28. |
|
Senna roemeriana |
Senna covesii |
|
Phenology | Flowering spring–early fall. | Flowering late winter–early fall. |
Habitat | Mesquite grasslands, chaparral, draws in shortgrass prairies, barren hillsides, desert washes, roadsides. | Sandy and gravelly desert washes, slopes, and stony hills, disturbed desert roadsides. |
Elevation | 100–2000 m. (300–6600 ft.) | 0–1200 m. (0–3900 ft.) |
Distribution |
NM; OK; TX; Mexico (Chihuahua, Coahuila, Nuevo León)
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AZ; CA; NM; NV; Mexico (Baja California, Sinaloa, Sonora)
|
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 | ||
Synonyms | Cassia roemeriana, Earleocassia roemeriana | Cassia covesii, Earleocassia covesii |
Name authority | (Scheele) H. S. Irwin & Barneby: Mem. New York Bot. Gard. 35: 282. (1982) | (A. Gray) H. S. Irwin & Barneby: Phytologia 44: 499. (1979) |
Web links |