Dalea sericea Lag.

  • Authors

    Rupert C. Barneby

  • Authority

    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.

  • Family

    Fabaceae

  • Scientific Name

    Dalea sericea Lag.

  • Description

    Species Description - Perennial herbs, diverse in habit and stature, the stems stout and stiffly erect, or slender and incurved-ascending, or humifusely radiating from a woody root and (in age) a short caudex, including peduncles (2) 2.5-15 dm tall, like the foliage silky- pilose throughout with subappressed and narrowly ascending, often mixed with some or many spreading hairs up to (0.8) 1-2.5 mm long, the leaves green or greenish- silvery, pubescent both sides but sometimes thinly so above; leaf-spurs 0.5-1 (1.5) mm long; stipules narrowly lance-acuminate or linear-caudate, (3) 4-11 (17) mm long, pilosulous dorsally, glandless, often purplish; intrapetiolular glands spiculiform, or 0; post-petiolular glands immersed, or 0; leaves subsessile or short-petioled, the primary cauline ones (1.5) 2-6 cm long, with (2) 4-5 (6) pairs of elliptic, oblanceolate, or oblong-elliptic, acute to short-acuminate, flat leaflets (4 ) 5- 20 ( 22) mm long; peduncles terminal and continuous with the main stem-axis or its (usually few) branches, (1) 1.5-5 dm long, often half or more than half the length of the whole plant; spikes very dense, oblong-cylindroid or the shorter ones ovoid when young, without petals (1) 1.3-2.1 cm diam, the densely pilosulous axis (1) 1.5-7 (8.5) cm long; bracts deciduous only with the ripe pod, lance-caudate, 4-9 mm long, the lowermost (often barren) firm, densely villous dorsally, the interfloral ones boat-shaped, embracing the calyx, pallid or roseate at base, broadly scarious-margined, the keel and tail livid and villous, the tail slightly shorter to much longer than the body; calyx 4.6-8.7 mm long, densely villous-pilose externally, the tube 2.5-3.3 mm long, its orifice oblique, the ribs filiform, little prominent, usually livid, the pallidly membranous intervals glandless or charged with ± 1-3 minute transparent glands, the narrowly subulate to lance-aristate, livid, plumose teeth (1.8) 2.5-5 (5.8) mm long, commonly as long up to 3 mm longer than tube, rarely a little shorter than it; petals wholly or largely violet purple, drying blue or bluish-purple, rarely reddish, the blade of banner sometimes with white (rubescent) eye or white except for partly blue margin or blue basal lobes, all glandless, the epistemonous ones low-perching, well below middle of androecium; banner 5.7-9 mm long, the claw (2.6) 2.8-4.8 mm, the deltate-cordate and obtusely shallowly 3-lobed or sometimes suborbicular, subacute to emarginate blade (3) 3.2-5 mm long, 3.2-5.2 mm wide; wings (5.1) 5.5-8.5 mm long, the claw 1.4-3.1 (3.5) mm, the elliptic-oblanceolate blade (3.8) 4.3-6.7 mm long, (1.5) 1.7-2.9 mm wide; keel 6.5-10 mm long, the claws (2.2) 2.4-4 (4.5) mm, the broadly obliquely obovate blades 4.3-6.8 mm long, (2.5) 2.8-4.3 mm wide; androecium 10- merous, 7-11 mm long, the longer filaments free for 1.5-2.5 mm, the connective usually minutely gland-tipped, the anthers (0.5) 0.55-0.8 (0.9) mm long; pod in profile varying from semi-ovate to deltate, 2.1-2.7 mm long, the ventral suture straight or slightly convex, the dorsal one strongly convex or abruptly incurved into the filiform prow, the valves hyaline in the lower half, thence thinly papery, densely ascending- pilose, eglandular; seed brown or olivaceous, 2.1-2.8 mm long; x = 7.

  • Discussion

    (Plate CXXXII)

    The superficially polymorphic D. sericea, a species common through the temperate highlands from west-central through southern Mexico into Guatemala and Honduras, is distinguished from all sympatric daleas by the combination of herbaceous growth-habit, pilose vesture, few (mostly four or five) pairs of flat expanded leaflets, and dense spikes of bluish-violet, sometimes white-variegated flowers borne aloft, well beyond the last leaves, on long naked peduncles. It resembles some members of sect. Cylipogon in habit and vesture, but differs in the simple crest of the pod and the blue, not yellow pigmentation of the petals. In the context of sect. Parosela, the close kindred of D. sericea seem to be the small-flowered annual species of the ser. Reclinatae immediately preceding.

    My concept of D. sericea is equivalent in scope to Rydberg’s Parosela Sericeae, a group of three taxa conceived and technically separated primarily in terms of growth-habit. Much of the now ample material can still be sorted neatly into Rydberg’s three categories, but much cannot, and there appear to be no morphological discontinuities within the complex of the sort expected in genuinely discrete species. The entity segregated by Rydberg under the misplaced epithet reclinata has some claims to recognition because, in addition to some weak morphological characters, it has acquired a distinct zonal range above that of typical D. sericea; it is maintained here as a newly described variety.