Dalea scandens var. occidentals

  • Title

    Dalea scandens var. occidentals

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea scandens var. occidentalis (Rydb.) Barneby

  • Description

    141c.  Dalea scandens (Miller) R. T. Clausen var. occidentals (Rydberg) Barneby

    (Plate CXXIX)

    Habit of var. paucifolia, the foliage always villosulous; primary leaves 2.5-5.5 (7) cm long, usually present only during fall months, with 7-11 (13) leaflets 8-18 (22) mm long, the leaves of short-shoots present January-April shorter, with only 59 smaller leaflets; peduncles mostly less than 3 mm long, a few of the earliest up to 1.5-2.5 cm; spikes 5-20 (25)-flowered, the axis 3-20 (30) mm long; bracts 3-5 (6.5) mm long; calyx (5.6) 6-8.9 mm long, villosulous from base, the tube 2.4-2.8 mm, the glands in each interval (2) 3-5 (6), mostly small, discrete, the dorsal tooth (3.2) 3.4-6.2 mm long; keel 5-6.3 mm, the claws 1.4-2.3 mm, the blades 3.3-4.2 mm long, 1.7-2.3 mm wide; androecium 5.8-7 mm long. — Collections: 21 (o).

    Arid hillsides and thickets in thorn-forest, near sea-level up to 600 m (± 2000 ft), coastal plain and foothills along the w. coast of Mexico from s. Sonora to s. Sinaloa, apparently disjunctly in s.-w. Jalisco (but to be expected in intervening Nayarit).—Flowering October to April. —Representative: Sonora. Alamos: Gentry 2938 (ARIZ, UC, US); Ripley 14,244 (ARIZ, CAS, F, NY, UC). Sinaloa. El Fuerte: Rose, Standley & Russell 13,619 (NY, US). Mocorito: Gentry 5732 (ARIZ, NY). Culiacan: typus. Mazatlan: Rose, Standley & Russell 13,695, 14,024 (NY, US); Ortega 6781 (BR, US). San Ignacio: Ortega 33 (MEXU); Gentry 5713 (ARIZ). Concordia: Ortega 6321 (M). Jalisco. La Huerta: McVaugh 23,043 (ENCB, MICH); Tomatlan: McVaugh 25277 (MICH).

    Dalea scandens (Mill.) R. T. Clausen var. occidentalis (Rydb.) Barneby, stat. nov., based on Parosela occidentalis (western) Rydb., N. Amer. Fl. 24: 115. 1920.— "Type collected at Culiacan, Sinaloa, October 25 to November 18, 1891, Edward Palmer 1783..."—Holotypus, NY! isotypi, some labelled "Lodiego, Oct. 9-15", ARIZ, UC, US!— Dalea occidentalis ((Rydb.) Riley, Kew Bull. 1923: 337. 1923; Wiggins, Contrib. Dudl. Herb. 3: 53. 1940.

    Parosela platyphylla (with flat leaflets) Rydb., N. Amer. Fl. 24: 115. 1920.— "Type collected on dry hills in the vicinity of Fuerte, Sinaloa, March 26, 1910, Rose, Standley & Russell 13527..." — Holotypus, US! isotypus, NY!

    Dalea blasiana (of San Bias) Jones, Contrib. West. Bot. 15: 138. 1929.— "No. 23040. San Bias Sinaloa, February 1, 1927." — Lectotypus (Morton, Contrib. U. S. Nat. Herb. 29: 102. 1945), UC (lacking at POM)! isotypi, GH, NY, UC, US!

    The var. occidentalis is weakly distinguished from var. paucifolia by a deeper calyx-tube charged with more numerous and smaller intercostal glands; on the average the petals are a little more ample and the calyx-teeth a trifle longer. In other respects the varieties are in close accord. As in var. paucifolia, the spikes may be either erect or (cf. Rose, Standley & Russell 14,724; Gentry 5732) nodding. The distantly allopatric var. vulneraria differs from var. occidentalis in the calycine characters just mentioned, and has furthermore slightly more numerous leaflets.

    The evaluation of Parosela occidentalis and P. platyphylla as trivial variants of one entity (Wiggins, 1940, p. 53) is unquestionably correct. The typus of the former was collected at the end of the rainy season and presents a foliose condition with many relatively long primary leaves with up to six pairs of leaflets, whereas that of P. platyphylla was collected in late March after the primary leaves had fallen and only shorter rameal leaves with 2-4 pairs of leaflets persisted on the plant. Together they document the ordinary seasonal sequence in their species as a whole.