Dalea hospes

Title

Dalea hospes

Authors

Rupert C. Barneby

Scientific Name

Dalea hospes (Rose) Bullock

Description

56.  Dalea hospes (Rose) Bullock

(Plate LXIV)

Shrubs with slender crooked trunk irregularly branching distally, 1.5-2.4 (3) m tall, glabrous to the inflorescence, the old bark gray, the younger woody branches striped lengthwise, the young twigs slender pliant, livid, smooth or distantly tuber- culate, the foliage green, the leaflets smooth or finely punctate above, either punctate or tuberculate beneath; leaf-spurs 0.3-0.8 mm long; stipules triangular-subulate, thin-textured, 0.5-1 mm long; intrapetiolular glands 0; post-petiolular glands conic, prominent, orange; leaves short-petioled, the main cauline ones (0.7) 1-2 cm long, with narrowly margined rachis and 2-4 (5) pairs of obovate-cuneate, obovate, or broadly oblanceolate, obtuse or emarginate, flat leaflets 3-10 mm long, the terminal trefoil usually larger than the rest, the rameal leaves smaller; peduncles leaf-opposed and terminal to branchlets, 0.5-3 (5) cm long; racemes loosely (5) 10-30 (35)-flowered, the glabrous axis finally (1) 1.5-5 cm long; bracts clasping young buds but early deciduous, broadly elliptic-ovate or ovate-acuminate, 1.8-3 mm long, submembranous, pallid or livid, dorsally glandular, minutely ciliolate; pedicels ascending 0.4-1.5 mm long; calyx 3.8-4.8 mm long, either glabrous or sparsely pilosulous externally, the orifice and inner face of teeth densely ciliolate, the tube pleated at base, 2.6-3.2 mm long, the ribs prominulous, the submembranous intervals charged with 1 (sometimes irregular) row of 3-5 honey- or orange- to livid-colored glands, the teeth unequal, the dorsal one broadly subulate, 0.9-1.8 mm long (not over 2/3 as long as tube), the rest broadly low-deltate and short-acuminate, often gland-spurred; petals pale greenish- yellow or ochroleucous, the banner (sometimes all) brownish-rubescent, all or only the banner gland-tipped, the epistemonous ones perched near middle of androecium (above mouth of calyx), 3.4-5.4 mm above hypanthium; banner 5.5-7 mm long, the claw 3-4.1 mm, the broadly ovate-deltate blade 2.9-3.6 mm long, 3.2-4.4 mm wide, recessed at base into a cornet; wings 4.8-5.2 mm long, the claw 0.7-1.2 mm, the blades oblong-oblanceolate ± 4.5 mm long, 2.4-2.7 mm wide; keel 6.7-8 mm long, the claws 2-2.2 mm, the broadly obovate blades 5.2-6 mm long, 3.1-3.8 mm wide; androecium 10-merous, 8-11 mm long, the longer filaments free for ± 2.4-2.8 mm, the anthers 0.6-0.8 mm long; pod 3-3.7 mm long, in profile triangular-obovate, the style-base latero-terminal, the prow slightly dilated (db 0.2 mm thick), the valves hyaline in lower half, thence papery, minutely gland-sprinkled, pilosulous; seed ochra- ceous, lustrous ± 2.3 mm long. — Collections: 22 (iii).

Brushy hillsides and rock-ledges in canyons, strongly calciphile, (850) 1020-2100, reportedly 2500 m (2825-7000, perhaps 8325 ft), locally plentiful on the e. slope and higher interior valleys of Sierra Madre Oriental in Nuevo Leon and immediately adjoining centr. Tamaulipas, from Monterrey s. to lat. 24° N, and n.-ward from Monterrey on outlying calcareous mountains to near Lampazos, Nuevo Leon at ±27° N. and in the same latitude w. into centr. Coahuila (Sas. de la Gloria and de la Madera). —Flowering irregularly, May to November .—Representative: Coahuila: Mueller 3156 (UC). Nuevo Leon: Mary Taylor Edwards 439 (ARIZ); Chase 7766 (ARIZ, F, NY); Mueller 2348 (F, GH, TEX); Mosquin 6574, 6594 (NY); Ripley & Barneby 13,590 (CAS, NY, US), 13,595 (CAS, MEXU, NY, US); Meyer & Rogers 2875 (BR, F). Tamaulipas: H. H. Bartlett 10,970 (F, MEXU, RENNER).

Dalea hospes (Rose) Bullock, Kew Bull. 1939: 196. 1939, based on Parosela hospes (host, to the stem parasite Pilostyles pringlei Rose) Rose, Contrib. U. S. Nat. Herb. 12: 272. 1909. — "Collected by C. G. Pringle in the Sierra Madre above Monterey, in 1888 (no. 1904, type) and 1903 (no. 11417); also by Dr. E. Palmer in the Caracol Mountains, Coahuila, in 1880 (no. 210)." — Holotypus (Pringle 1904), US! isotypi, BR, F, M (2 sheets), NY (2 sheets), UC! paratypi: Pringle 11,417, F, L, US! Palmer 210, NY, US!

An oddly but strongly characterized dalea, which might be described as a drawn-out version of D. frutescens with pedicellate flowers and pale yellow petals. Its kinship to D. frutescens is expressed by likeness in foliage, calyx, and other flower-parts, but the growing plants are superficially very different, D. frutescens being a low bushy shrub usually many stemmed, whereas D. hospes develops one or few long skinny trunks (rarely 1.5 cm diam) that branch 1-2 meters above ground into a narrow and irregular or sometimes more symmetrically doming panicle of branchlets. The range, habitat, and habit of growth of D. hospes are suggestively reminiscent of D. melantha var. berlandieri which has, perhaps not coincidentally, a similarly racemose inflorescence and petals of a pale ivory or lemon yellow. In practice the latter is separated directly by its externally long-pilose, long-toothed calyx, but it seems not impossible that D. hospes may have arisen in the first place as the progeny of miscegenation between D. frutescens and D. melantha.

Populations of D. hospes differ in pubescence of the calyx, sometimes glabrous and glossy externally as in D. frutescens, sometimes thinly pilosulous, but always densely ciliolate around and within the short-toothed orifice. Mosquin noted bees (near Monterrey) and various Hymenoptera (Galeana) as insect-visitors to the flowers.