Astragalus crassicarpus var. trichocalyx

Commonly taller and coarser than the preceding varieties, more rarely quite slender and decumbent, except for the calyces and pedicels thinly strigulose-pilosulous with loosely ascending or subappressed hairs up to 0.5-0.9 (1) mm. long, the stems glabrous or nearly so toward the base, the herbage green, or grayish only in youth, the leaflets either glabrous or thinly pubescent above; leaves (5) 7-18 cm. long, with 21-33 elliptic or lance-elliptic and acute or subacute, or sometimes all broadly oval or lance-oblong and obtuse, or (especially in some lower leaves) truncate-emarginate leaflets (4) 7-24 mm. long; peduncles usually erect or incurved-ascending; pedicels 4-7.5 mm. long in fruit; calyx (6.6) 8.3-11 mm. long, the pallid tube (5.2) 6—8.1 mm. long, (2.7) 3.5—5 mm. in diameter, the teeth (1.4) 1.9—3.3 mm. long; banner (16) 17.8-24.5 mm. long, 7.4-10.8 mm. wide; wings (14.2) 16-19 mm. long, the claws 7-9.5 mm., the blades (8.4) 9-11.5 mm. long, 2.4-4 (4.4) mm. wide; keel (12.2) 13.7-17.4 mm. long, the claws (6.5) 7.3-9.4 mm., the blades (6.3) 6.5-8.3 mm. long, 3.2-3.8 mm. wide; pod (only rarely humistrate) broadly oblong-ellipsoid, plumply ovoid, plumply obovoid, or globose, 13.5—2.1 cm. in diameter; ovules 48—77.—Collections: 66 (i); representative: Pl. Gray. Exsicc. 1249, 1250; Cory 55,057 (OKLA, WS), 57,014 (CAS, SMU); Engelmann 1014 (NY, WIS); Waterfall 6993 (OKLA, TEX); Fassett 17,356 (WIS, WS), 17,492 (WIS); an extensive series from Missouri collected by Steyermark (MO).

Open rocky woodlands and coming out onto the edge of prairies, pastures, and along roadsides, mostly below 1400 feet, scattered but sometimes locally plentiful, northeastern Texas and eastern Oklahoma, east into western Arkansas, and through Missouri into westcentral Illinois.—Map No. 101.—Late March to July, the fruit ripening in midsummer or later, rarely flowering again in fall.

Astragalus crassicarpus var. trichocalyx (Nutt.) Barneby ex Gl., New I11. Fl. 2: 241. 1952, based on A. trichocalyx (with hairy calyx) Nutt. ex T. & G., Fl. N. Amer. 1: 332. 1838. —"Plains of Arkansas, Nuttall! & Dr. Leavenworth! who also found it in Texas!"—No spm. found (1962) in Nuttall’s own herbarium (BM); lectotypus, labeled by Nuttall "Astragalus *trichocalyx. Ark.," NY! isotypi, PH, and labeled "A. carnosus. Arkansa." G, K!—Geoprumnon trichocalyx (Nutt.) Rydb. in Bull. Torr. Club 53: 163. 1926. Astragalus mexicanus var. trichocalyx (Nutt.) Fern. in Rhodora 39: 317. 1937.

The Ozark ground-plum, var. trichocalyx, is ordinarily very distinct because of its coarse ascending stems and its villous-tomentulose calyx and pedicels. The pubescence is fugacious, however, for the calyx is deciduous by circumscissile fission above the disc, and the pedicels become glabrate as they thicken and elongate beneath the ripening fruit. The petals are commonly ochroleucous, but not rarely suffused with pinkish-lilac. Slender forms with decumbent stems (Waterfall 9365, OKLA, SMU) are occasionally met with, and in these the fruits are humistrate as in other forms of A. crassicarpus. The pod is ordinarily large, 2.5 cm. long or longer and at least 1.5 cm. in diameter, but it is sometimes no larger than that of var. crassicarpus and is exactly like the commonest type of var. Berlandieri. Possibly the fruits of var. trichocalyx persist longer on the receptacle than in other forms of the species, but too little material with truly ripe pods has been seen to settle this interesting point.

Although there is no reason to suppose that var. trichocalyx and var. Berlandieri are more closely related to each other than either is to var. crassicarpus, they have been confused since early times. Gray (1864, p. 193) treated them as synonyms (under A. mexicanus), although he mentioned some Texan forms, doubtless referable to genuine var. Berlandieri, which seemed "too close" to A. caryocarpus (= our var. crassicarpus). Fernald distinguished them as varieties of A. mexicanus, but his key characters (1950, p. 906-7) purporting to distinguish A. mexicanus from A. caryocarpus serve only to distinguish material from the Gray’s Manual range. The record of var. trichocalyx from Louisiana (Fernald; Rydberg) has not been confirmed by specimens.