Dalea carthagenensis var. capitulata

  • Title

    Dalea carthagenensis var. capitulata

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea carthagenensis var. capitulata (Rydb.) Barneby

  • Description

    139e.  Dalea carthagenensis (Jacquin) Macbride var. capitulata (Rydberg) Barneby

    (Plate CXXVI)

    Shrubs to 1-2 m tall with pliant branches, appearing glabrous to the spikes, but young twigs and leaves of short-shoots thinly villosulous; primary cauline leaves (1) 1.5-4.5 cm long, often lacking from flowering material, with (7) 9-15 (17) leaflets (3) 4-10 (12) mm long; spikes all subcapitately few-flowered, the earliest terminal to main branches shortly pedunculate, the majority terminal to axillary spurs and appearing sessile, the whole inflorescence becoming an interrupted spike of depressed-globose to low-ovoid heads 10-13 mm diam, the axis of each 2-7 mm long; bracts 2.34 mm long, the lowest sometimes glabrous dorsally but ciliate, the rest villosulous dorsally; calyx silky-pilose all over, 5.3-7.6 mm long, the tube 2.1-2.4 mm, the intercostal glands (3) 4-8, small, distinct but prominent, the straight, plumose teeth 3.1-5 mm long; banner 3.1-3.8 mm, its claw 1.4-1.8 mm, its blade 1.7-2.4 mm long; keel 1.9—5.9 mm long, the claws 1.5-1.8 mm, the blades 3.7-4.1 (4.4) mm long, 2-2.4 mm wide; androecium 5.2-6.7 mm long; 2n = 14 (Mosquin). — Collections: 21 (vi).

    Arid hills and valley floors, on a variety of sedimentary, volcanic, and alluvial soils, locally very abundant, forming large associations sometimes crowded into thickets, 700-1560 m (2700-5200 ft), arid interior lowlands of s. Mexico, around the n.-w. periphery of Balsas Depression in e. Michoacan, s.-w. Mexico and Puebla, e. to the Tehuacan Desert and headwaters of Rio Papaloapan in Puebla, and especially common in the valley of centr. Oaxaca; one record from Tehuantepec (Cerro Pozorio).— Representative: MichoacAn. Tiquicheo: Moore et al. 5705 (BH, MEXU, UC). Mexico. Temascaltepec: Hinton 7564 (ARIZ, F, NY, Z), 8572 (ARIZ, F, NY, US, W, Z). Puebla. Tehuitzingo: Ripley & Barneby 14,573 (CAS, GH, MEXU, MICH, NY, US). Tehuacan: Purpus 461 (GH, UC). Coxcatlan: Ripley & Barneby 14,722 (CAS, DAO, NY). Zapotitlan de Salina: Ripley & Barneby 14,716 (NY). Oaxaca. Tomellin: L. C. Smith 443 (GH). Etla: Ripley & Barneby 14,614 (NY). Oaxaca de Juarez: Conzatti 1675 (GH, OKLA); Liebmann 4615 (F). Miahuatlan: Ripley & Barneby 14,644 (NY).

    Dalea carthagenensis (Jacqu.) Macbr. var. capitulata (Rydb.) Barneby, stat. nov., based on Parosela capitulata (with small headlike spikes) Rydb., N. Amer. Fl. 24: 113. 1920.— "Type collected in Oaxaca, December 8, 1901, Conzatti & Gonzalez 1262..." — Holotypus, GH! clastotypus (fragm.), NY!— D. capitulata (Rydb.) Harms, Verh. Bot. Ver. Brandenb. 65: 88. 1923.

    Parosela tehuacana Rydb., N. Amer. Fl. 24: 113. 1920.— "Type collected at Tehuacan, Puebla, November 7, 1901, Holway 53..." — Holotypus, US!— Dalea tehuacana (Rydb.) Bullock, Kew Bull. 1939: 199. 1939.

    Specimens of var. capitulata collected at full anthesis suggest drought-inhibited var. barbata in which branchlets of the second and subsequent orders of ramification have failed to develop, so that the whole inflorescence is reduced to an interrupted spiciform raceme of small subsessile heads. Earlier in the year, however, before the primary cauline leaves have fallen, a foliose aspect of the same thing presents at least a few pedunculate heads terminal to main branchlets. At this stage var. capitulata is distinguished from var. barbata by its glabrescent or glabrate foliage and, more securely, by a shorter calyx-tube and substantially smaller keel-blades and androecium. The range of the two varieties is, moreover, significantly different.

    Rydberg distinguished within the present var. capitulata two species, supposed to differ in number and size of leaflets. In Oaxaca the leaflets do tend to be relatively small and numerous (up to 11-15), whereas they tend to be larger and fewer (up to 7-9) in the Papaloapan drainage in Puebla. However one collection from the valley of Oaxaca (Conzatti 5203, NY) has leaves with 13 leaflets up to 8 mm long, that is of a size correct for Parosela tehuacana but of a number proper for P. capitulata. The material collected since Rydberg’s revision provides a much fuller picture of these shrubby winter-flowering daleas than was accessible fifty years ago, and no longer suggests any noteworthy racial segregation. The var. capitulata was collected first by Karwinski (nos. 5775, 5776, M) in 1827.