Dalea plantaginoides

Rupert C. Barneby

21.  Dalea plantaginoides Barneby

(Plate XLIV)

Erect annuals, glabrous to the inflorescence, 1.5-4.5 dm tall, simple and monocephalous when small, more commonly branching either below or above the middle, the stems and narrowly ascending, monocephalous branches stiff, sharply angled, sparsely punctate but otherwise smooth, the sparse foliage green, the leaflets smooth above, gland-dotted beneath; leaf-spurs 0.4-1 mm long, their margins decurrent into the ribs of the stem; stipules narrowly subulate, stiff, 0.5-1.8 mm long; intrapetiolular glands minute, impressed; post-petiolular glands small, barely prominent; main cauline leaves (1) 1.5-3.4 cm long, petioled, with broadly thick-margined, punctate rachis, the lowest and uppermost 3-, rarely 1-foliolate, the majority 5-foliolate, the leaflets linear or linear-elliptic, acute, gland-mucronulate, (5) 8-23 mm long, up to 1 mm wide, thick-textured, the margins involute, the dorsal keel prominent when dry; peduncles terminal to all the branches, usually less than 10, sometimes only 1 per plant, 2.5-7 cm long; spikes dense, ovoid-oblong to cylindric, 8-25 mm long, without petals 5-6 mm diam; bracts persistent, broadly ovate to deltate- or rhombic-ovate, very shortly acuminate, 2.5-3.5 mm long, 1.8-3 mm wide, carinate below the middle, broadly scarious-margined, the middle green or purplish, verrucose with prominent reddish glands, the outermost glabrous dorsally, the upper ones villosulous at base, all ciliolate, the tips ± squarrose; calyx 2.1-2.5 mm long, glabrous up to the thinly pilosulous and ciliolate teeth, the ovoid, membranous tube ± 1.3- 1.5 mm long, the ribs slender, scarcely prominent, the intervals glandless, the orifice oblique, the ventral sinus recessed behind the banner, the ovate-triangular, acute teeth of nearly equal length, 0.6-1.2 mm long; petals opening white, the banner rubescent in age, the caducous inner ones perched just below separation of the filaments; banner 2.7-3 mm long, spatulate, the claw and round, scarcely emarginate, flat blade of nearly equal length; wing and keel petals not strongly differentiated in form, the claws obscure or very short, the blades obovate to elliptic-oblong, obtuse, ± 1.7-2 mm long; androecium 10-merous, becoming 3.3-4.3 mm long, the longest filaments free for ± 1.5-1.8 mm, the connective gland-tipped, the anthers 0.3 mm long; pod (not seen ripe) ± 2 mm long, obovoid-ellipsoid, keeled both dorsally and ventrally beyond the middle, the style-base terminal but excentric, the valves papery, thinly pilosulous distally, glandless. — Collections: 3 (o).

Pine or pine-oak forest, 1600-2000 m (± 5300-6700 ft), apparently rare and local, but inconspicuous and perhaps overlooked, known only from the w. edge of Balsas Depression on the headwaters of Rio Tepalcatepec, about the flanks of Volcan Tancitaro in w. Michoacan and on Sierra de los Corales in s.-e. Jalisco. — Flowering October to December. —Material: Michoacan: Tancitaro (type). Jalisco. Tecalitlan: Los Corales, Rzedowski 17,418 (ENCB, MICH); 15 km w. of Pihuamo, Feddema 2212 (MICH).

Dalea plantaginoides (plantain-like, of the small, conelike spikes) Barneby, sp. nov., D. cliffortianae Willd. manifeste affinis sed foliolis foliorum caulinorum 1-2 (nec 3-7)- jugis, pube bractearum calycisque brevius dentati breviori ac sparsiori, petalisque interi- oribus albis nec purpureo-coeruleis statim recognita. A D. exigua Barneby, allopatrica sed foliolis paucijugis habituque simili, foliolis toto glabris, calycis inferne glabrati dentibus abbreviatis, petalis albis nec purpureis, necnon androecio 10- nec subpentamero longius distat. — Michoacan : hillside in pine forest, 2000 m, Tancitaro, distr. Uruapan, Nov 11, 1940, G. B. Hinton 15,665. - Holotypus, NY; isotypi, K, RENNER, UC, US.

This strongly characterized and highly modified annual dalea is related to D. cliffortiana and to D. exigua. The former is found in the same latitudes but generally below the pine belt; it differs in having at least three, mostly four to six pairs of leaflets in all but an occasional depauperate leaf, in the densely pilose, longer-toothed calyx, and in the bright blue or purplish-blue inner petals. Features common to D. cliffortiana and D. plantaginoides are glabrous foliage and an androecium of at least nine members. The only related species with 3-5-foliolate cauline leaves are D. exigua and D. confusa, both of which have leaflets thinly ciliate with long, weak, spiral hairs, purple inner petals, and an androecium variably reduced to 4-7 members. The species most nearly resembling D. plantaginoides in habit isi). exigua, native to similar environment in the pine forests of the northern Sierra Madre Occidental, over 800 km northward from Tancitaro. The annual dalea common in the Michoacan pinelands is D. obreniformis, differing in its many, broader, thin-textured leaflets and bright blue petals.

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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