Chamaecrista nictitans
Chamaecrista fasciculata
partridge pea, sensitive partridge or wild sensitive pea, sensitive partridge pea, sensitive pea, wild sensitive-pea
partridge pea, partridge sensitive-pea, showy partridgepea, sleepingplant
erect, incurved ascending.
erect.
(1.5–)2–8(–9)[15–21] cm;
petiole (1.5–)2–7 mm;
extrafloral nectary 1(or 2), near mid petiole, stipitate;
leaflets (6–)8–28(–32)[–40] pairs, blades usually straight, sometimes falcate, linear, narrowly oblong, or oblong-elliptic, (3–)4–26 × 1–3 mm.
2.5–11 cm;
petiole (2–)2.5–9 mm;
extrafloral nectary 1(–3), sessile or shortly stipitate;
leaflets (7 or)8–22(–26) pairs, blades linear-oblong, oblong, oblong-oblanceolate, or -elliptic, apex mucronulate to subacute, (5.5–)7–20(–23) × (1.3–)1.5–5(–6) mm.
1(or 2)-flowered, axillary.
1–4(or 6)-flowered, supra-axillary.
0.5–4[–16] mm;
bracteoles mid pedicel.
(6–)8–22(–26) mm;
bracteoles distal to mid pedicel.
calyx greenish, sepal venation reticulate;
corolla yellow, sometimes fading pinkish, petals to 3.5–8(–9)[–16] mm;
stamens [2–]4–8[or 9];
anthers yellow-orange or red, to (1.4–)1.6–3[–9.5] mm, different sizes;
ovary usually hairy throughout, rarely glabrate.
calyx greenish, sepal venation reticulate;
corolla yellow, fading brown or orange, rarely whitish, 2–4 petals with reddish maculate at claw, to 10–23 mm;
stamens 10;
anthers all or some yellow, yellow and red-tipped, red, red-brown, or red-violet, to (5.5–)6–10.5 mm;
ovary often hairy, sometimes glabrous.
straight, linear-oblong, [14–](15–)18–48(–56)[–78] × [2.4–]2.5–5.5(–5.8) mm.
straight or curved, linear-oblong, (3–)3.5–6.5(–10) × (25–)30–75(–85) mm.
[1.9–](2.2–)2.4–3.4[–3.7] mm.
(2.8–)3.2–4.8(–6.3) mm.
= 16.
Chamaecrista nictitans
Chamaecrista fasciculata
Varieties 13 (3 in the flora).
Chamaecrista nictitans is distinguished from the closely similar C. fasciculata (and C. deeringiana) by its globose-ovoid floral buds, which are ovoid-acuminate in the latter two species. All three varieties in the flora area belong to subsp. nictitans and are characterized by two to nine fertile stamens, while all other varieties have ten fertile stamens (they belong to the other subspecies): subsp. brachypoda (Bentham) H. S. Irwin & Barneby, subsp. disadena (Steudel) H. S. Irwin & Barneby, and subsp. patellaria (Colladon) H. S. Irwin & Barneby (H. S. Irwin and R. C. Barneby 1982). The key to varieties in the flora is adapted from Irwin and Barneby.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Due to its high morphological variation, Chamaecrista fasciculata has been characterized by a history of shifting species and infraspecific taxonomic boundaries. Even its current definition is not satisfactory (H. S. Irwin and R. C. Barneby 1982), especially considering the high similarity (and probably very close relationship) with other partially sympatric species of Chamaecrista, such as C. chamaecristoides, which occurs in Texas, and C. deeringiana in the southeastern United States. Chamaecrista fasciculata also closely resembles C. nictitans but can be distinguished by its ovoid-acuminate floral buds, which are globose-ovoid in C. nictitans. Chamaecrista fasciculata is the first non-papilionoid legume to become a model species in genomics (S. R. Singer et al. 2009). It has been used to address research questions ranging from climate change (J. R. Etterson 2004) to specialized pollination biology (C. B. Fenster 1995) and ant-plant interactions (M. T. Rutter and M. D. Rauser 2004; R. S. Rios et al. 2008).
Cassia chamaecrista Linnaeus is a rejected name that pertains here.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaflet blade margins ciliolate, some hairs 0.4+ mm; ovules 8–19. | var. leptadenia |
1. Leaflet blade margins glabrous or hairs to 0.4 mm; ovules 5–10. | → 2 |
2. Stems and petioles glabrous or hairs whitish, to 0.7 mm. | var. nictitans |
2. Stems and petioles covered with hairs yellow or orange reddish, 1–2.5 mm. | var. aspera |
WildflowerSearch
iNaturalist
USDA Plants Database
Go Botany
IL Wildflowers
KS Wildflowers
LA Plants
MD Biodiversity
MI Flora
MN Wildflowers
MO Plants
