Dalea obovata
Rupert C. Barneby
31. Dalea obovata (Torrey & Gray) Shinners
(Plate LI)
Coarsely leafy herbs, from potentially perennial but short-lived orange roots, sometimes flowering the first season, up to 5.5 dm tall, densely lanate-pilose throughout with fine lustrous spreading and ascending spiral hairs up to 1.2-2.2 mm long, the stout, remotely micro-glandular stems erect and incurved-ascending, simple or few- branched either from below the middle or distally, densely leafy almost up to the massive cylindric spikes (but primary cauline leaves drought-deciduous), the foliage gray (the vesture rusty when dried), the leaflets under the hairs green above, not punctate beneath; leaf-spurs up to 1.8 mm long; stipules narrowly lance-acuminate or -caudate, thinly herbaceous or submembranous, pallid or castaneous, 3-8 mm long, plumose; intrapetiolular glands 0; post-petiolular glands small but prominent; leaves shortly petioled, the primary cauline ones (2) 2.5-5 cm long, with remotely micro- punctate, narrowly wing-margined rachis and 3-5, commonly 4 pairs of obovate, obtuse or abruptly short-acuminate (sometimes penicillate-acute), flat leaflets up to (0.8) 1-1.6 cm long, the stalked terminal one not or little larger than the last pair, the leaves of axillary spurs similar but smaller, with only 2-3 pairs of shorter leaflets; peduncles stout, continuous with the stem, 0-3 cm long; spikes very dense, the many- ranked flowers contiguous, the whole ovoid in bud quickly becoming ovoid-oblong and then cylindroid, without petals (1.2) 1.4-2 cm diam, the axis 3.5-11 cm long; bracts deciduous but the interfloral ones held fast until fall of the fruit, 5.5-11 mm long, subdimorphic, the lowest ovate- to broadly lance-acuminate from cuneate base, not forming a calyculus, the rest very broadly to narrowly spatulate-acuminate, the narrowed, membranous-margined stalk-like base folded to clasp base of calyx, the flat or shallowly concave blade 1.8-5 mm wide, papery or becoming so, commonly castaneous or castaneous-tipped, dorsally pilose-barbate and charged with few small livid glands, plumose-ciliate, glabrous within, the triangular to acuminate tail shorter than blade, pilosulous to tip; calyx 3.3-5.8 mm long, densely pilose from very base with straight, ascending and spreading hairs up to 1-2.4 mm long, the rather broadly campanulate tube (1.3) 1.4-2 (2.1) mm long, ± recessed behind banner but the orifice little oblique, the castaneous or pallid ribs filiform, the broad hyaline intervals flat, glandless or charged with 1-2 minute pale glands, the teeth broadly to narrowly triangular-aristate, 2-4 mm long, subhomomorphic but the ventral pair a trifle broadest, the tips all subincurved, castaneous, plumose; petals whitish, drying ochroleucous, the epistemonous ones deciduous on expansion from sockets at or just below separation of filaments; banner (3.5) 4-7 mm long, the filiform claw (1.5) 1.9-3.4 mm, the ovate-oblong or oblong, erect, glandless blade (2) 2.2-2.9 (3.1) mm long, 1.2-2 mm wide; epistemonous petals 2.5-4 mm long, the narrowly oblong-oblanceolate blades ± 2-3.2 mm long, 0.5-0.9 mm wide, truncately or cuneately narrowed at base into a claw 0.4-0.7 mm long; androecium (4.5) 5-6.6 mm long, the column 3-4.4 mm, the free filaments only ± 1/2-1/3 as long, up to 1.6-2.5 mm long, the connective gland- tipped, the pallid anthers 0.6-0.75 mm long; pod obliquely obovate in profile, 2.7-3 mm long, the style-base lateral, the prow slenderly ribbed, the valves thinly papery, glabrous but opaque at base, pilosulous distally; seed pale, lustrous, ±1.7 mm long; 2n = 14 (Mosquin). —Collections: 18 (ii).
Deep sandy and silty soils of the Gulf Coastal Plain in s. Texas, sometimes accompanied by D. emarginata, D. phleoides, and D. lanata, locally plentiful around the Gulf itself from the mouth of Rio Grande to the inner arms of Matagorda Bay in Jackson County, n. on the Brazos River to Austin and Brazos counties, w. to the foot of Balcones Escarpment in Wilson and Medina counties, and (cf. Wemple, 1970, map 11) to an isolated station on the Rio Grande in s. Valverde County; to be expected in n.-e. Coahuila. — Flowering April to July, sometimes again in fall and early winter. — Representative: Lindheimer 40 (NY, UC, W); Wemple 724 (NY); Palmer 230 (NY, US); Lundell 8851 (TEX); Ripley & Barneby 14,786 (DAO, NY); McCart 8325 (OKLA).
Dalea obovata (Torrey & Gray) Shinners, Field & Lab. 17: 84. 1949, based on Petalostemon obovatum (obovate, of the leaflets) T. & G., Fl. N. Amer. 1: 310. 1838. — "Texas, Drummond " — Holotypus, Drummond 128 of Coll. II, NY (herb. Torr.)! probable isotypus, labelled "between Brazoria and San Felipe", Drummond 128 of Coll. Ill, K! — Kuhnistera obovata (T. & G.) A. Hell., Bull. Torrey Club 23: 122. 1896.
Dalea agastachya (great-spiked) Moricand, Pl. Nouv. Amer. 65, tab. XLIV. 1839 — "Hab. in Texas. Berlandier. No. 2002" — Holotypus, 2 sheets, one dated 1829, the other 1832, G! isotypi, some from "between Nueces and Medina rivers", K, NY, P, W! —Kuhniastera obovata (Moric.) O. Kze., Rev. Gen. 192. 1891.
An unmistakable dalea, different from any in or near its range of dispersal in the long shaggy pubescence, the few ample leaflets, and the immense subsessile spikes of tiny fleeting flowers, the whitish ribbons of the epistemonous petals being thrown off almost as soon as they expand.
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.Multimedia:
