Monographs Details: Baptisia bracteata var. glabrescens (Larisey) Isely
Authority: Isely, Duane. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. New York Bot. Gard. 25 (3): 1-264.
Description:Distribution and Ecology - Range of w segment of species except for se Texas and Louisiana (see key). Habitats diverse: N and w part of range: usually upland prairie fragments, pastures or short-grass range and on sandy to clay soils. S: open, oak or mixed bottomland or hillside woodlands, savannah-grassland, clay ridges, limestone hills, outcrops and prairies, commonly persistent in pastures and disturbed areas. March-April (s); May-June (n).
Discussion:B. leucophaea Nutt. (1818).
Lasinia bracteata (Ell.) Raf. (1837) pro parte, excl. basionym.
B. leucophaea var glabrescens Larisey (1940);
B. bracteata var glabrescens (Larisey) Isely (1978).
B. laevicaulis x leucophaea pro parte.
Baptisia bracteata var glabrescens (as B. leucophaea) is the most common and wide-ranging Baptisia of the central states, and anyone botanizing in the spring or early summer will encounter it. It is usually easily recognized, even at a distance, by its low spreading habit and secund racemes of pale yellow flowers. The clusters of stems form little flat “bushes” broader than high, and the racemes dangle out of the sides. Pod formation is frequently poor.
In the northern and western portion of its range, Baptisia bracteata var glabrescens is almost invariably conspicuously pubescent. From middle Missouri southward, the pubescence diminishes and the frequence of glabrate forms increases. In southern Arkansas, northern Louisiana and Texas, some plants are not only glabrate but the leaflets of the upper leaves approach in dimensions those of var laevicaulis, although those of the lower leaves remain narrower. To show this variance approximately on the distributional map (No. 17), I have codified it as follows:
Typical Baptisia bracteata var glabrescens. Plants pubescent; leaflets 3-5.5 r.
Baptisia bracteata var glabrescens variant 1. Plants glabrate; leaflets 3-5.5 r. This is mostly var glabrescens sensu Larisey, but remains B. leucophaea of most subsequent authors and identifications. It has essentially the leaf proportions of typical var glabrescens, but is glabrous or glabrate, and some populations mapped as variants 1 and 2 include both glabrate and pubescent plants.
Baptisia bracteata var glabrescens variant 2. Plants glabrate; lower leaflets 2.5-4.5 r, upper leaflets 1.8-3 r, broader than the lower and approaching those of var laevicaulis. Such plants have been variously determined as var leucophaea, var laevicaulis or leucophaea-laevicaulis intermediates. Some populations from the vicinity of Hot Springs, Arkansas, could justifiably be identified as var laevicaulis, but since they are distant from that variety otherwise, I have retained them with variant 2.
Baptisia bracteata var glabrescens (?) variant 3. Plants pubescent; leaflet dimensions essentially those of var laevicaulis. I have seen but few specimens of variant 3 and its genetic relations are problematic. Because the plants come from within the range of var glabrescens, I have assigned them to that variety.
Turner and associates (Turner and Alston, 1959; Alston and Turner, 1963; Brehm and Alston, 1964) have studied hybridization between Baptisia bracteata var glabrescens and other species.
Distribution:United States of America North America