Dalea candida var. candida

  • Title

    Dalea candida var. candida

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea candida Willd. var. candida

  • Description

    41b.  Dalea candida (Michaux) Willdenow var. candida

    (Plate LVI)

    Steins usually erect, virgate, (4) 5-10 dm tall, paniculately branched distally, or branched from near middle upward, the panicle then long and narrow, exceptionally monocephalous and then exceptionally slender; stipules narrowly lanceolate to broadly subulate, (1) 1.5-5.5 mm long; primary cauline leaves 3-6 cm long, with 2-4, most often 3 pairs of broadly to narrowly elliptic-oblanceolate, acute to shortly acuminate, less often obtuse (then gland-mucronulate) leaflets up to (1.2) 1.5-3.5 cm long, the foliage mostly deep green when fresh, the leaflets sometimes drying verdigris above, pale beneath; bracts 3-5.5 mm long; spikes (6) 6.5-9.5 (10) mm diam, the glabrous or puberulent axis (1) 1.5-5.5 (7) cm long; calyx always glabrous except for ciliolate teeth, the intercostal panels of tube charged at apex with usually 1 small, sometimes inconspicuous gland; epistemonous petals 3.6-5.2 mm long, the blades varying from oblong to elliptic or oblanceolate, either truncate or cuneate at base, 2-2.9 mm long, 1.3-1.7 mm wide; 2n = 14 (2 counts, cited by Wemple, 1970, p. 12).—Collections: 124 (i).

    Rich prairies, mostly below 450 m (1500 ft), of centr. United States and adjoining Canada, extending s. and s.-e. into open oak- or oak-pine-woodland, in hill-country of n.-w. Arkansas up to 630 m (2100 ft), widespread and locally common around the Mississippi embayment and the lower Missouri valley e. of 100° W, n. (and up to 650 m) to s. Saskatchewan, s. Manitoba, and adjoining Ontario, e. to Illinois, centr. Kentucky, centr. Tennessee, and s.-w. Alabama, w. interruptedly to the Gulf Coastal Plain in s.-e. Texas and inland to the longitude of Austin and Fort Worth, w. to centr. Oklahoma, centr. Kansas, and (following the Platte River up to 1020 m) interruptedly to w. Nebraska; cf. Wemple, 1970, map 7.— Flowering late-May to August, rarely again in fall. — Citation of representative var. Candida superfluous.

    Dalea Candida (white-flowered) Michaux ex Willdenow, Sp. Pl. 3: 1337. 1802.— Holotypus, presumably at B, not seen; isotypus cited under the next! — Petalostemum candidum Michaux, Fl. Bor.-Amer. 2: 49. 1803, an independent proposition treated retroactively as an inadvertent new combination. — "in Tennassee et in regione Illinoensi." —"Prairies des Illinois", Michaux, P (herb. Michx.)! — Psoralea Candida (Michx.) Poir. in Lamk., Encycl. Meth. 5: 694. 1804. Kuhniastera Candida (Michx.) O. Kze., Rev. Gen. 192. 1891.

    As noted by Wemple (1970, p. 50), var. Candida is much less variable than var. oligo- phylla, ordinarily characterized by the combination of ample, 7-foliolate primary leaves, tall virgate stems, and dense cylindric flower-spikes. The latter may be arranged in a fewheaded corymbose panicle or, with development of several or many of the usually inhibited axillary branchlets, in a long narrow thyrse, the lateral spikes then smaller and shorter than the terminal ones.

    The white prairie-clover seems to have been extremely common over the high-grass prairie region before arrival of the plough; nowadays it is seen most often along highways and railroads, or in the glade environment of the southeastern woodlands. The clear white flowers are fragrant and often besieged by butterflies, bees and various hymenoptera.