Dalea gypsophila
Rupert C. Barneby
116. Dalea gypsophila Barneby
(Plate XCVII)
Dwarf subshrubs 1-2 (2.5) dm tall, glabrous to the flower-spikes, the older branches decumbent, adventitiously rooting, thereby forming diminutive thickets up to 1 m diam, the young flowering stems incurved-ascending and erect, densely leafy, simple or branched, densely tuberculate with small but prominent warts, the foliage green, the leaflets smooth above, beneath gland-tuberculate and also microscopically pallid-papillate; leaf-spurs less than 0.7 mm long; intrapetiolular glands 0-1; post- petiolular glands prominent, subulate or prickle-shaped; leaves shortly petioled, (5) 7-14 mm long, with very narrowly margined, tuberculate rachis and (4) 5-8 pairs of crowded, linear-oblong or -oblanceolate, emarginate but bluntly gland-mucronulate, thick-textured, folded leaflets 1.5-3.5 (4) mm long; peduncles terminal, mostly solitary, 1-2.5 cm long, the inflorescence projected well above the leaves; spikes loosely (6) 10-22-flowered, without petals 6-8 mm diam, the ascending flowers when pressed subcontiguous but mostly 2-ranked, the axis becoming (3) 6-25 (35) mm long; bracts tardily deciduous, broadly ovate or lance-ovate, (2.2) 2.5-3.5 mm long, greenish or livid becoming castaneous, glandular-tuberculate dorsally, the lowest glabrous or nearly so externally, ciliolate, the upper ones finely pilosulous below middle; calyx sessile, 4-4.6 (5) mm long, silky-pilosulous or loosely strigulose with ascending hairs up to 0.3-0.45 mm long, the tube 2.1-2.6 mm long, the ribs subfiliform, little prominent, the relatively firm intervals charged with 1 (the ventral pair with 2) rows of 3-7 small glands, the triangular-subulate, minutely gland-spurred teeth unequal, the dorsal one 1.1-1.9 (2.5) mm long, the ventral pair shorter and broader, the orifice ± oblique; petals bicolored, the banner opening creamy-yellow, often purple-edged, early rubescent, the epistemonous ones dark plum-purple, perched below middle of androecium (1.5-2.5 mm above hypanthium), all or all but the banner charged with a small subapical gland; banner 4.5-5.4 mm long, the claw 2.3-3 mm, the deltate-cordate or suborbicular emarginate blade recurved through ± 45°, recessed at base into a shallow comet, 2.7-3.7 mm long, 2.8-4.2 mm wide; wings 3.5-6.3 mm long, the claw 1-1.6 mm, the oblong or lance-oblong blade 2.9-5 mm long, 1.4-2.5 mm wide; keel 5.2-6.6 (7.2) mm long, the claws 1.6-2.2 (2.4) mm, the broadly ovate-elliptic blades 3.8-4.7 (5.3) mm long, 2-3.2 mm wide; androecium 10-merous, 6.7-7.6 (8) mm long, the longer filaments free for 2.2-2.5 mm, the connective gland-tipped, the yellow anthers 0.65-0.8 mm long; pod in profile triangular- obovate, 2.2-2.6 mm long, the short style-base latero-terminal or nearly so, the sutures slender, the valves hyaline and glabrous in lower half, thence thinly papery, pilosulous, and charged with a few small glands; seed 2-2.3 mm long; 2n = 14 (Mosquin).— Collections: 9 (iii).
Valley flats and low gullied hills in thin pine-pinyon woodland, confined to gypseous clay soils, 1830-2070 m (6100-6900 ft), locally abundant near the watershed of Sierra Madre Oriental from Galeana s.-e. 60 km just into the n. edge of mpo Aramberri, lat. 24° 15' to 24° 50' N, in s.-centr. Nuevo Leon. — Flowering June to November.— Representative: Nuevo Leon: C. & M. Mueller 1082 (F, GH, MICH); Correll & Johnston 19,861 (RENNER); G. N. Jones 22,914 (WIS); Ripley & Barneby 13,792 (CAS, MEXU, MICH, NY, US), 14,775 (DAO, NY); Shreve & Tinkham 9726 (ARIZ, GH, MICH).
Dalea gypsophila (addicted to gypsum) Barneby, sp. nov., inter congeneres omnes foliolis (glaberrimis) dorso dense minutim papillosis unica, a D. capitata Wats, petalis epistemoneis saturate livido-purpureis (nec flavis), a D. radicanti Wats, sympatrica sed verosimiliter minus affini caulibus elevatim verruculosis, racemo pleiantho, tubo calycino extus sericeo, foliolisque minus numerosis (4-8 nec 6-11-jugis) procul distans. — Fruti- culosa infra spicas glaberrima humilis, caulibus vix 2.5 dm altis decumbentibus radicanti- bus; folia 7-14 mm longa, foliois (4) 5-8-jugis lineari-oblongis vel -oblanceolatis com- planatis 1.5-4 mm longis carnosulis; spicae laxe 6-22-florae axis maturus (3) 6-35 mm longus; bracteae demum deciduae ovatae 2.2-3.5 mm longae; calycis sessilis dense sericei tubus 2.1-2.6 mm longus, dentes triangulari-subulati inter se inaequales, dorsalis longior 1.1-1.9 (2.5) mm longus; petala bicoloria, vexillo ochroleuco saepe purpureo-marginato mox rubescenti, epistemoneis livido-purpureis, carinae laminis 3.8-5.3 mm longis.— Nuevo Leon: 2 1/2 mi (± 4 km) s. of Galeana, oct. 29, 1964, Ripley & Barneby 13,577.— Holotypus, NY; isotypi, CAS, ENCB, GH, K, MEXU, MICH, NY, UC, US, Z.
A localized and taxonomically isolated species of uncertain relationship, possibly allied to the yellow-flowered D. capitata found, also at least sometimes on gypsum, in the same region. Like some forms of the latter, the plants of D. gypsophila spread by means of adventitious roots arising from the lower side of decumbent woody branches, eventually forming continuous patches a meter or more across. The very small, crowded leaflets are seen under magnification to be densely papillate, a feature not encountered elsewhere in Dalea. The narrow spikes of silky-pilosulous calyces rise vertically well above the crowded foliage but are far from showy, only one or two flowers being open at one time and these neither large nor vivid. The banner opens yellowish but soon fades reddish, and the epistemonous petals are deep plum-purple or faded crimson, sometimes against the background of white gypseous clay appearing almost black.
South of Galeana D. gypsophila is associated with the almost equally local D. radicans, like it insofar as it also forms diffuse masses of procumbent twigs, although this achieved by procumbently arching stems that root at tip. It differs further in the remotely leafy stem, smooth (non-papillate) leaflets, and short raceme of distinctly but shortly pedicellate, externally glabrous or glabrescent calyces. In one place D. gypsophila was found growing within an extensive colony of D. greggii, another procumbent, tip-rooting shrub- let, but very different in its gray-silky foliage, few leaflets, and denser ovoid spike of rose- purple flowers. Despite the ostensibly remote kinship between them, an apparent hybrid was found among them, a single patch, probably clonal in character (Ripley & Barneby 14,776), combining the vesture of D. greggii with the microtuberculate leaf-surface of D. gypsophila.
While several calciphile daleas occur on gypsum and some seem to prefer it, D. gypsophila is one of very few that is (so far as known) confined to it. It forms, in fact, a characteristic element of a specialized gypsophyte florule that includes Notholaena bryopoda Max., Linum modestum C. M. Rogers, Polygala oedophylla Blake, Hesperozygis ciliolata Epl. and H. pusilla Irving, and Pectis bracteata Wats.
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:
