71a.  Dalea obovatifolia Ortega var. obovatifolia

(Plate LXXIV)

Perennial (sometimes precociously flowering) and herbaceous, the stems commonly decumbent to weakly assurgent, (1) 2.5-4.5 (6) dm long; pubescence variable, but stems distally and leaf-rachis normally ± pilose, the leaflets sometimes ciliate, the stems and leaflets sometimes glabrous; leaf-spurs mostly 0.5-2.5 mm, stipules (2) 3.5-6 mm long; spikes (1) 2.5-8 (11) cm long; flowers usually large (as given in key), subtended commonly by short-tailed bracts; 2n = 14, 7 II (Mosquin).— Collections: 59 (iv).

Plains and open hillsides, usually in depauperate (secondary) grassland, but entering, perhaps originating in, the oak-pine belt, locally plentiful on eroded and gullied land, 1350-2650 m (4500-8500 ft), common in the Valley of Mexico, Distrito Federal and adjoining Mexico and Hidalgo, probably adjoining e. Michoacan, n.-e. in Hidalgo to Jacala, s.-e. into highland Puebla; apparently disjunct in s. San Luis Potosi (Sa. de Alvarez) and adjoining n.-e. Jalisco (Ojuelos); centr. Oaxaca. Not recorded from Guanajuato, Queretaro, or Tlaxcala, but to be expected.— Representative: Jalisco: McVaugh 16,907 (MICH). San Luis Potosi: Rzedowski 5267 (ENCB). Hidalgo: Chase 7119 (ARIZ, F, NY, transitional in some respects to var. uncifera); Rzedowski 23,335 (ENCB). Mexico (incl. D.F.): Pringle 3181 (BR, F, M, NY, UC, US, W); Ripley & Barneby 14,523 (DAO, NY); Matuda 21,059 (MEXU, NY). Puebla: Balls 4506 (K, UC, US); Rose & Hay 5661 (NY, US); Mosquin et al. 6657 (NY). Oaxaca: Andrieux 447 (G, M, W); Galeotti 3241 (BR, W); Ripley & Barneby 14,606 (NY, US), 14,677 (DAO, NY).

Dalea obovatifolia (with obovate leaflets) Ortega, Decades 32. 1797. — "Habitat in insula Cuba. Floret in mense Augusto et Septembri in Reg. Horto Matritensi e seminibus missis per D. Sesse."— No typus found at MA; neotypus: "Ex regno Mexicano culta in hort. Mat. anno 1797", MA (herb. Cav.)!

Psoralea mutabilis (changeable, of the petal-color) Cav., Icones 4²: 65, Pl. 394. 1798 (maio 14—cf. Taxon 10: 78. 1961). —"Habitat in insula Cuba, et in Regno mexicano... colitur in Regio horto Matritensi, ubi floruit Iulio et Augusto 1797." — Holotypus: "Ex regno Mexicano culta in hort. Mat. anno 1797", MA (herb. Cav.) = neotypus of preceding! isotypus, BM! — Dalea mutabilis (Cav.) Willd., Sp. Pl. 3: 1339. 1801. Parosela mutabilis (Cav.) Cav., Descr. Pl. 186. 1802.

Parosela attenuata (gradually drawn out, of the bracts) Rydb., N. Amer. Fl. 24: 82. 1920. — "Type collected in Sierra de San Felipe, Oaxaca, October 26, 1894, Charles E. Smith 547..." — Holotypus, NY! isotypi, F, US!—Dalea attenuata (Rydb.) Cowan, Brittonia 8: 60. 1954.

Parosela bicolor sensu Rydb., N. Amer. Fl. 24: 83. 1920. — Non Dalea bicolor Willd.

As seen in and near the Valley of Mexico, var. obovatifolia takes the form of a diffuse perennial herb with several stems radiating from the root-crown and bearing in late summer one or more oblong spikes of relatively large hyaline calyces. Pubescence is variable in density, the more and less hairy phases corresponding with Rydberg’s Parosela bicolor and P. mutabilis. In central Oaxaca var. obovatifolia occurs not only in secondary (often heavily eroded) grassland but also in openings of sunny oakwoods, the stems there becoming more erect. This last phase, which suggests a large-flowered var. uncifera, was segregated by Rydberg as P. attenuata, but hardly deserves taxonomic notice.

First grown in Europe at the Madrid Botanical Garden, D. obovatifolia passed into rather wide cultivation in the stoves of Old World gardens, remaining in favor for about fifty years, and then apparently dying out. Bonpland had it at Malmaison (P) in 1813, where it was painted by Redoute. In 1823 Hooker figured a plant in Exotic Flora (vol. 1, t. 43) that had grown under glass at Glasgow, and in the following year it appeared in Curtis’s Botanical Magazine (t. 2486), where the origin of the model, grown at Chelsea, is said to be C. F. Otto, of the Berlin Botanical Garden. Hooker mistakenly called his plant D. bicolor, and Sims (in Curtis) followed the synonymy, but adopted the older name, D. mutabilis. It is under the last name that Loudon figured a small branchlet in one of her nosegays (Ladies’ Fl.-Gard. Ornam. Perenn. 1: t. 35) in 1843.