Dalea crassifolia
Rupert C. Barneby
67. Dalea crassifolia Hemsley
(Plate LXXI)
Tall suffruticose herb with a woody root up to 1-1.5 cm diam just below the crown and 1-several erect or virgately ascending stems up to 8-15 dm long, glabrous to the spikes, the striate, sparsely gland-sprinkled stems simple and rather densely leafy up to the middle or beyond, paniculately branching distally and the foliage abruptly reduced in the inflorescence, the leaflets thick-textured, bicolored, green above, pallid-glaucescent and strongly gland-dotted beneath; leaf-spurs very short or obsolete; stipules triangular-subulate, livid, up to 1 mm long, deciduous; intrapetiolular glands minute, impressed; post-petiolular glands small but prominulous, obtuse or lens-like, orange; main cauline leaves (drought-deciduous, largely shed by late anthesis) 4_7.5 cm long, with narrowly thick-margined, gland-dotted rachis and (10) 1727 ( 33) pairs of rather crowded, elliptic or oblong-elliptic, obtuse but dorsally gland- mucronulate, shallowly boat-shaped, dorsally keeled leaflets 1.5-4.5 (5) mm long, the uppermost leaves shorter, with fewer leaflets of the same type but smaller; peduncles terminal to branches of the panicle, the one central one leaf-opposed, mostly 1.5-5 cm long but often appearing longer due to reduction (or suppression) of the uppermost leaves; spikes densely many-flowered, cylindric or becoming so, without petals or androecia 9-11 mm diameter, the densely pilose axis becoming 1.5-5.5 cm long; bracts deciduous, narrowly lance-acuminate or -caudate, the lowermost (sometimes persistent) glabrous dorsally, the rest villosulous dorsally, glabrous within, all livid-nigrescent distally, charged with small livid or orange glands, the tail surpassing the flower-buds; calyx 5-7.2 mm long, densely silky-pilose externally with ascending, finally spreading and plumose, spiral hairs up to 1-1.4 mm long, the tube 2.2-2.7 mm long, the ventral sinus recessed behind the banner (the orifice thus oblique), the orange or livid ribs slender becoming prominent, the membranous intervals charged with irregularly seriate, small yellow glands, the triangular-acuminate or -aristate, gland-spurred teeth of nearly equal length, the dorsal one 2.7-4.8 mm long, nearly always longer than the tube; petals apparently whitish drying cream-colored, perhaps lilac when fresh (but not purple), the banner faintly rubescent, the banner sometimes sparsely gland-sprinkled, the keel sometimes minutely gland-tipped, the inner ones elevated ± 1.2-1.5 mm above the hypanthium rim; banner 5.3-7.5 mm long, the claw 3-4 mm, the deltate-cordate blade scarcely recurved, acute or subacute at apex, open at base, 2.6-3.5 mm long, ± as wide; wings 5.5-7.3 mm long, the claw 2.6-3.7 mm, the oblong-oblanceolate blade 3.2-4.2 mm long, 1.3-1.8 mm wide; keel 6.1-8.2 mm long, the claws 2.7-3.8 mm, the obliquely ovate blades 3.8-4.7 mm long, 2.5-3 mm wide; androecium 10-merous, 6.7-8 mm long, the longest filament free for 2.2-2.6 mm, the pallid, gland-tipped anthers 0.55-0.7 mm long; pod not seen, but the ovary closely resembling that of D. pectinata. — Collections: 3 (o).
Hillsides in pine or oak and pine forest, ± 1500 m, apparently rare, known only from the Sierra Madre between Mazatlan and Durango, either in Sinaloa or adjoining Durango, and from the coast range of extreme western Jalisco in the municipios of San Sebastian and Mascota. — Flowering January to March. — Sinaloa or Durango: typus. Jalisco: San Sebastian trail to Mine La Sabala, Mexia 1657 (BM, CAS, F, G, GH, MICH, NY, UC, US). Mascota to San Sebastian, E. W. Nelson 4063 (US).
Dalea crassifolia (thick-leaved, of the plump leaflets) Hemsl., Diag. Pl. Nov. 40. 1878. —"North Mexico, Sierra Madre (Seemann, 2190)..." — Holotypus, K! isotypi, BM, US (fragm.)! — Parosela crassifolia (Hemsl.) Rose, Contrib. U. S. Nat. Herb. 12: 272. 1909.
Because the plant body is glabrous up to the silky-plumose spikes and the leaflets of the main cauline leaves are very numerous (mostly 17-27 pairs), it has seemed most convenient for key purposes to contrast D. crassifolia with D. polystachya, easily distinguished by its rose-purple or vivid blue petals and looser spikes of relatively short-toothed calyces. Probably its closest relative, however, is D. similis, which has essentially the same inflorescence and individual flower together with leaves of like complexity but clad throughout with a mantle of soft, villous-tomentulose hairs. It might even be suspected that these two species, both discovered by Seemann somewhere in the Sierra Madre between Mazatlan and Durango, represent no more than marked pubescence-variants of one. However the leaves of D. similis are paripinnate, having lost the terminal leaflet, and the lowest pair of leaflets is perceptibly, even though only a little longer than all succeeding pairs, which diminish upward along the rachis. All leaves of D. crassifolia are of the imparipinnate type normal in Dalea, and the lowest pair is not larger than the rest. The less closely related D. pulchella, glabrous to the spikes like D. crassifolia but with the enlarged basal pair of leaflets found in D. similis, is sympatric with both these species on the Durango-Sinaloa boundary and with D. crassifolia in western Jalisco. Its denser head of vivid pink-purple flowers and small, almost round, often notched leaflets distantly arranged along the rachis distinguish it at a glance. Nothing is on record about the fresh color of the flower in D. crassifolia. The petals appear whitish or straw-colored in dried specimens, as do those of D. similis. Gentry found the inner petals of the latter lavender contrasting with a white banner, and it is likely that those of D. crassifolia are similar.
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:
