Dalea foliosa

Rupert C. Barneby

40.  Dalea foliosa (Gray) Barneby

(Plate LV)

Leafy perennial herb 3-8 dm tall, glabrous to the inflorescence, the stout erect and incurved-ascending, angular-ribbed, pallid or purplish stems either spurred or branched near middle, always paniculately branched distally, the spikes terminal to all upper branchlets, the foliage green, the leaflets somewhat bicolored, dark (when dry often verdigris) green above, paler and punctate beneath; leaf-spurs 0.5-1.8 mm long; stipules linear-lanceolate or setiform, 1.5-5.5 mm long, becoming dry and brittle; intrapetiolular glands small; post-petiolular glands small but prominent, obtuse; leaves sessile or almost so, the primary cauline ones 3-5.5 cm long, with openly grooved, wing-margined, minutely punctate rachis and 9-14 (15) pairs of oblong- oblanceolate to -elliptic, obtuse but then abruptly sharply short-acuminate, dorsally keeled, mostly flat leaflets up to 5-10 mm long, the shortly stalked terminal one no larger than last pair, the spur-leaves smaller, with fewer (mostly 4-9) pairs of shorter leaflets; peduncles 0-2 cm long; spikes very dense, the contiguous flowers horizontally spreading, the whole ovoid becoming cylindroid, without petals 8-10 mm diam, the glabrous or minutely puberulent axis 1.5-4.5 cm long; bracts deciduous only with the calyx and pod, subtended by spiculiform bracteoles up to 0.4-0.8 mm long, the lowest sometimes longer and firmer than the rest, lance-acuminate or -caudate, narrowly pallid-margined, otherwise green becoming brown or purplish, glabrous within and dorsally, minutely ciliolate; calyx 3.8-4.4 mm long, bluntly 10-angled, glabrous externally, the teeth densely pilosulous within and the orifice hence appearing ciliolate, the membranous, symmetrically campanulate tube scarcely recessed dorsally, 2.4-2.7 mm long, the thick but not prominent ribs becoming castaneous, the intervals narrow, castaneous-flecked with a narrow hyaline central panel, glandless, the teeth heteromorphic, the three dorsal ones triangular-lanceolate up to 1.3-1.7 mm long, the ventral pair almost as long but ovate-triangular, all firm, green becoming castaneous, the margins ± involute; petals lavender-purple, concolorous, glandless; banner 5.2-6 mm long, the claw 2.8-3.6 mm, the broadly ovate-suborbicular, strongly hooded blade shallowly cordate at base, 2.1-2.5 mm long, 2.6-3.2 mm wide; epistemonous petals 3-3.6 mm long, the linear-oblong obtuse blades slightly hooded at tip, cuneately narrowed at base into a claw 0.4-0.7 mm long; androecium 5.4-7.2 mm long, the column 2.6-3.7 mm, the free filaments 2.7-3.7 mm long, the connective gland-tipped, the anthers 0.6-0.85 mm, reddish, the pollen golden-orange; pod in profile half-obovate, 2.5-3 mm long, the ventral suture nearly straight to shallowly concave, the prow slender, the valves hyaline only at very base, thence papery, glabrous, minutely gland-sprinkled distally; seed pallid, ± 1.8-2 mm long; 2n = 14 (Mosquin).— Collections: 13 (o).

Notably bicentric in dispersal: limestone cedar glades and open calcareous barrens of centr. Tennessee, from Nashville Basin s. into n. Alabama (Franklin and Morgan counties; cf. Rhodora 69: 383); and on thinly wooded bluffs and stony river-flats of upper Illinois River and its tributaries the Fox and Kankakee rivers in n.-e. Illinois (cf. Gamhill, 111. Biol. Monogr. 22 (4): 47. 1953); cf. Wemple, 1970, map 4.— Flowering late June to September. —Representative: Illinois: Umbach 1896, 1995, 5715 (WIS); Calkins, from Ottowa, La Salle Co. (WIS). Tennessee: Gattinger distrib. Curtiss 570 (NY); Baskin s. n. in 1966 (DAO, pods, NY); Krai 29,001 (OKLA); Isely & Wemple 9420 (NY). Alabama: Baskin & Caudle 509, 517 (US).

Dalea foliosa (Gray) Barneby, comb. nov., based on Petalostemon foliosus (leafy) Gray, Proc. Amer. Acad. 7: 336. 1867.— "Banks of Fox River, Kane Co., Illinois, Burgess Truesdale, 1867. Also near Nashville, Tennessee, Mr. Hatch, 1854." — Lectoholotypus, Truesdale in 1867, GH! isotypi, K, NY! paratypi, Hatch in 1854, GH, MO! — Kuhniastera foliosa (Gray) O. Kze., Rev. Gen. 192. 1891.

An unmistakable species, notable for its many pairs of leaflets, in this respect differing from all prairie-clovers east of the Mississippi. My concept is traditional and in full agreement with Wemple (1970, p. 51, fig. 10D). The bicentric range closely resembles that of Astragalus tcnnesseensis Gray (cf. Barneby, Mem. N. Y. Bot. Gard. 13: 769, map 103), likewise taxonomically isolated, but seemingly a western element in the eastern flora. Plants grown from seed received from J. Baskin, collected at the southern edge of Nashville city, have proved fully frost-hardy on eastern Long Island, flowering profusely almost throughout summer and setting abundant seed. The ecology and dispersal of D. foliosus have been described in detail by Baskin & Baskin (Rhodora 75: 132-139 + map. 1973) who regard it as a diminishing species, probably extinct in the northern lobe of its range and threatened in Tennessee.

References: [Article] Barneby, Rupert C. 1977. Daleae Imagines, an illustrated revision of Errazurizia Philippi, Psorothamnus Rydberg, Marine Liebmann, and Dalea Lucanus emen. Barneby, including all species of Leguminosae tribe Amorpheae Borissova ever referred to Dalea. Mem. New York Bot. Gard. 27: 1-892.

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