Dalea tomentosa var. psoraleoides

  • Title

    Dalea tomentosa var. psoraleoides

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea tomentosa var. psoraleoides (Moric.) Barneby

  • Description

    101b.  Dalea tomentosa (Cavanilles) Willdenow var. psoraleoides (Moricand) Barneby

    (Plate XCIV)

    Essentially as var. tomentosa except for the (nearly always) externally glabrous calyx-tube, small whitish or faintly pink-tinged petals, and short androecium. — Collections: 78 (viii).

    Brushy and grassy hillsides, ascending into oak-woods or rarely into the pine belt, 600-2100 m, exceptionally lower (to 80 m on river sands of Rio Motagua in Izabal, Guatemala), widespread and common, though often appearing as individuals rather than in colonies, in the Neovolcanic Belt from the basin of Lago Chapala, Jalisco, to s. Mexico and Morelos; Sierra Madre del Sur in Guerrero and Oaxaca, and thence through the highlands of Chiapas, s. Guatemala (especially common), and Honduras, to Esteli, Nicaragua; in Mexico also apparently disjunct on the w. slope of Sierra Madre Occidental in s. Sinaloa. — September to February. —Representative: MEXICO. Sinaloa: Ripley & Barneby 14,020 (CAS, NY); Ortega 5295 (MEXU). Jalisco: McVaugh 13,324 (MEXU). Michoacan: Ripley & Barneby 13,394 (MEXU, NY, US), 14,104 (NY). Morelos: Pringle 9044 (F, MEXU); Ripley & Barneby 14,555 (NY). Guerrero: Hinton 9598 (F, NY), 11,527 (NY, RENNER, UC, US). Oaxaca: Galeotti 3159 (BR); Franco in 1842 (W). Chlapas: Alush Shilom Ton 403, 1247 (US); Laughlin 473 (US). GUATEMALA. Huehuetenango: Steyermark 51,747 (F). Baja Vera Paz: Kellerman 6344 (F, US). Izabal: Steyermark 38,297 (F). Zacapa: Steyermark 42,691 (F, NY). Sacatep£quez: Steyermark 59,225 (F). SololA: Kellerman 6357 (F, US). Guatemala: Molina 13,470 (F). Jalapa: Standley 76,754, 77,116 (F). Chiquimula: Steyermark 30,654 (F). Jutiapa: Steyermark 32,023 (F). HONDURAS. Comayagua: Standley & Chacon 6932 (F). F. Morazan: Molina 8792 (F). El Paraiso: Williams & Molina 11,202 (F, NY). NICARAGUA. Esteu: Williams & Molina 20,169 (NY, WIS).

    Dalea tomentosa (Cav.) Willd. var. psoraleoides (Moric.) Barneby, comb. nov., based on D. psoraleoides (resembling some Psoralea) Moric., Mem. Soc. Geneve 6: 533, tab. IV. 1833. — "Hab. in Mexico prope Cuernavaca." — Holotypus, Berlandier 1027, collected Oct 12, 1827, G! isotypi, OXF, W! —Parosela psoraleoides (Moric.) Rose, Contrib. U. S. Nat. Herb. 10: 104. 1906 ("psoralioides"). Parosela tomentosa var. psoraleoides (Moric.) Macbr., Contrib. Gray Herb., New Ser. 65: 18. 1922.

    Dalea vulcanicola (from the habitat) Donn. Sm., Bot. Gaz. 56: 52. 1913. — "Volcan Atitlan, Depart. Solola, Guatemala, Febr. 1906, W. A. Kellerman n. 5780..." — Holotypus, US!

    Petalostemon chiapense (of Chiapas) T. Brandg., Univ. Calif. Pub. Bot. 10: 408. 1924. -"Collected in mountains near Hacienda Monserrate, Chiapas. [Purpus] No. 9142." -Holotypus, collected in Sept 1923, UC! isotypi, F, GH, MEXU, NY, US!

    A coarse plant but inconspicuous, the tiny, whitish or dimly pink flowers transient and little exserted. Although adult plants become decisively shrubby or even arborescent, with a thin crooked trunk, growth is rapid and the first flowers are ordinarily produced at the close of the first season. At this stage the plant consists of a single leafy virgate stem bearing from the middle upward a succession of short branchlets, each terminating in a spike of flowers. The following year several stems may arise from the trunk close to the ground, especially if the primary leader is cut or damaged, but more often much of the primary axis persists, becoming woody and striped lengthwise, and gives rise distally to one or several virgate panicles, each equivalent to that of the first season. Later on the plants become irregularly branched, but the panicle of spikes, at whatever level it may originate, remains essentially uniform.

    The var. psoraleoides is extremely common in the highlands of Guatemala and again along the south slope of the Neovolcanic Belt in Mexico. At about the longitude of Lago Chapala in eastern Jalisco it is abruptly replaced by var. tomentosa, but then reappears, beyond the range of var. tomentosa, in quite typical form, on the Pacific slope in southern Sinaloa. Probably var. tomentosa is the derived form which has become dominant in a small enclave within the range of the species.