Monographs Details: Chamaecrista nictitans subsp. nictitans var. nictitans
Authors:Howard S. Irwin, Rupert C. Barneby
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.
Family:Caesalpiniaceae
Synonyms:Chamaecrista nictitans (L.) Moench, Cassia chamaecrista L., Cassia nictitans L., Cassia procumbens L., Chamaecrista procumbens (L.) Greene, Cassia chamaecrista f. pubicaulis Kuntze, Cassia multipinnata Pollard, Cassia nictitans var. multipinnata (Pollard) J.F.Macbr., Cassia multipinnata var. nashii Pollard, Cassia aspera var. mohrii Pollard, Chamaecrista aspera var. mohrii (Pollard) Pollard ex A.Heller, Chamaecrista nictitans (L.) Moench, Chamaecrista mohrii (Pollard) Small ex Britton & Rose, Chamaecrista nictitans var. commixta Pollard & Maxon, Cassia nictitans var. commixta (Pollard & Maxon) Millsp., Cassia nictitans var. hebecarpa Fernald, Cassia nictitans var. leiocarpa Fernald, Cassia chamaecrista L.
Description:Species Description - Annual but sometimes (especially s.-ward) basally lignescent in age, at anthesis 1-7 dm, the stem either erect, when varying from simple to distally branched, or diffusely branched from base, commonly puberulent or distally, with the leafstalks, pilosulous with incumbent or spreading-incurved hairs up to 0.2-0.7 mm, the lfts glabrous or less often puberulent on both faces, their margins smooth or minutely scabrous-ciliolate with hairs not over 0.15 mm, occasionally glabrous throughout. Lvs (disregarding short simpler early ones) 2—7 cm, petiole 2—7 mm, gland usually solitary, rarely 2, discoid or shallowly saucer-shaped, red, mostly orbicular in outline, 0.3-1 mm diam, usually stipitate but the stipe varying from slender to stout and distally dilated, the whole 0.3-1 mm tall and either much longer or much shorter than diam of the head; lfts (6-)8-23(-26) pairs, linear-oblong or narrowly oblong-elliptic (4-)6-26 mm, the midrib slightly excentric, the secondary venation either faint or prominulous. Pedicels at anthesis up to 2 mm, in fruit 1-3.5 mm; sepals 3.2—5.3 mm; long petal obovate-cuneate or spatulate, 3.5-6.5(-7) mm, either much or only a trifle longer than the oblique cucullus; stamens 4-5, ±0-2(-3) interior staminodia or degraded stamens, the long anthers (1.4—)1.7—2 8 mm- style 1-1.4 mm, slightly dilated upward and 0 25-0.4 mm diam at apex; ovary’usually strigulose sometimes minutely pilosulous or quite glabrous; ovules (4-)5-10 Pod (unless deformed) 18-43 x (2.8-)3.2-5.5(-5.8) mm, the valves commonly puberulent, less often shortly pilosulous or fully glabrous; seeds dark brown, sometimes paler toward the hilum, sublustrous, faintly pitted, 2.7-3.4 mm—Collections: 249.—Fig. 52.

Distribution and Ecology - Open woods, thickets, sandy fields and pastures, shores, hedgerows, and waste places, locally abundant and an early invader of land cleared for agriculture or by logging, widespread over e. and s.-e. United States but n. of the Tennessee V. and s. New York discontinuously scattered and perhaps only immigrant since Colonial times, Massachusetts and s.-w. Vermont to centr. Illinois, s. to centr. Florida, the Gulf Coast, s.-centr. Oklahoma, and Texas e. of Edwards Plateau; cf. Pullen, 1963, fig. 9; Turner, 1959, map 35; Isely, 1975, map 49.—Fl. (VII-) VUII-frost, or s.-ward well into winter.

Discussion:

The var. nictitans, endemic to United States, has been subject to intense analysis in recent decades (Pullen, 1963; Isely, 1975). Internal variation, as we perceive it, is documented by the foregoing description, while differential characters distinguishing it from allied forms have been noted under vars. aspera and mensalis immediately preceding. The var. nictitans stands in relation to the whole neotropical Ch. nictitans complex as does Cassia nomame (Sieb.) Kitagawa to the paleotropical complex of Ch. mimosoides (L.) Greene. Each has migrated northward into a cold-winter climate and acquired the ability to survive severe frost in the form of seeds.

Distribution:United States of America North America| Tennessee United States of America North America| New York United States of America North America| Massachusetts United States of America North America| Vermont United States of America North America| Illinois United States of America North America| Florida United States of America North America| Oklahoma United States of America North America| Texas United States of America North America|