Dalea polygonoides

  • Title

    Dalea polygonoides

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea polygonoides A.Gray

  • Description

    26.  Dalea polygonoides Gray

    (Plate XLVII)

    Slender annuals, glabrous to the inflorescence, 0.5-3 dm tall, when depauperate simple and monocephalous but usually branched from the base upward or the stems simple from the base and branched only distally, purplish at base becoming green and angular upward, sparsely glandular-verruculose, the foliage of rather thick texture, the leaflets green above, pallid and punctate beneath; leaf-spurs up to 0.5 mm long, sometimes subobsolete; stipules subulate to subulate-caudate, 0.6-2 mm long, mostly livid or brownish; intrapetiolular glands confluent into a single, subulate or triangular spicule up to 0.3 mm long; post-petiolular glands hemispherical, prominent, yellow or orange; leaves (0.7) 1-3 cm long, slender-petioled, with narrowly margined, usually sparsely glandular rachis and (1) 2-3 (4) pairs of narrowly oblong-oblanceolate, emarginate or retuse leaflets 5-12 (15) mm long, the terminal one longer than but arising at the same point as the last pair, all easily and quickly reflexed at dusk or when picked; peduncles mostly 1.5-7 (15) cm long, subobsolete in some young or depauperate individuals; spikes at anthesis moderately dense, becoming looser in fruit, at first ovate in outline, becoming ovate-oblong to cylindric, without petals 5.5-8 (9) mm diam, the thinly pilosulous or glabrous axis becoming (5) 8-25 (30) mm long; bracts persistent, subdimorphic, the lowest broadly obovate-flabellate to rhombic- ovate, short-acuminate, 2-4 mm long, the interfloral ones narrower, rhombic-oblanceolate to -spatulate, pallid and membranous in the proximal livid distally and charged dorsally with a few large, orange or pale yellow glands, all glabrous dorsally and ciliolate, or the upper ones sometimes thinly pilosulous dorsally; calyx at anthesis 2.8-4 mm long, distended and slightly accrescent in fruit, thinly pilose externally with silvery hairs or the tube glabrous and only the teeth and orifice pilose-ciliolate, the tube recessed behind the banner, at first obconic-campanulate 1.6-2.1 mm long, 1.2-1.6 mm diam, pleated at base, the ribs slender but prominent, usually livid, the intervals hyaline, charged with 1 (2) large orange glands, the livid teeth triangular- aristate, gland-spurred, 1.3-2 mm long; petals pale rose-purple, eglandular or the banner charged with a few tiny, scattered glands, the wings and keel early deciduous, perched well below separation of the filaments; banner 2.7-3.8 mm long, the claw 1.1 -1.8 mm, the flabellate blade 1.4-2.3 mm long, 1.2-1.5 mm wide; wings 2-2.5 mm long, the claw 0.8-1.1 mm, the narrowly oblanceolate, minutely auricled blade 1.3-1.6 mm long, 0.3-0.6 mm wide; keel (2) 2.4-2.9 mm long, the claws 0.8-1.5 mm, the half-obovate blades 1.3-1.9 mm long, 0.7-1 mm wide; androecium (6) 7-9- merous, 2.2-3.5 mm long, commonly with only 5 fertile members, the rest with effete or greatly reduced anthers, the longer filaments free through 0.45-0.7 mm, the connective minutely gland-tipped, the fertile anthers nearly round in outline, ± 0.2 mm diam; pod exserted from the calyx-tube, obliquely obovoid-pyriform in profile, 2.5-3 mm long, the style-base lateral, the filiform prow strongly convexly arched, livid- nigrescent, the valves hyaline proximally, thinly papery, pilosulous but not glandular distally; seed 1.5-1.9 mm long; 2n = 7 II (Mosquin). — Collections: 33 (ii).

    Open slopes and grassy or gravelly flats in pine-forest, 1950-2770 m (6500-8300 ft), local but forming colonies, widespread around the upper watershed of the Gila River in centr. and s.-e. Arizona (Yavapai to s. Apache, Greenlee, and Cochise Co) and s.-w. New Mexico (Catron, Grant, and w. Sierra Co.), e. in New Mexico to the s. end of Sangre de Cristo Mts. (San Miguel Co.) and White Mts. (Lincoln Co.)., the Davis Mts. in trans-Pecos Texas, and s. (as now known seemingly interruptedly) along Sierra Madre Occidental to w.-centr. Durango. — Flowering September-October. —Representative: UNITED STATES. Arizona. Yavapai: Goodding 88-46 (NY). Coconino: Deaver 6067 (NY). Apache: Gould & Robinson 5-80 (UC). Pima: Shreve 5408 (UC). Greenlee: Pinkava et al. 13,657 (NY). Cochise: Blumer 1652 (L, NY, W). New Mexico: Catron: Metcalfe 463 (NY, UC). Sierra: Metcalfe 1410 (NY, UC, WIS). Grant: Rusby 84 (NY). San Miguel: Rose & Fitch 17,600 (NY). Lincoln: Wooton 525 (NY). Texas. Jeff Davis: Correll 33,767 (RENNER). MEXICO. Chihuahua. Madera: A. S. Leopold 245 (UC). Ciudad Guerrero: Pringle 1213 (F, NY, MEXU). Durango. V. Ocampo: Reveal & Hess 3101 (NY). Durango: Mosquin 6829 (NY). El Salto: Ripley & Barneby 13,984 (CAS, DS, NY).

    Dalea polygonoides (resembling some annual knotgrass) Gray, Pl. Wright. 2: 39. 1853.—"Pebbly bed of mountain torrents, near the copper mines, New Mexico [ = Santa Rita, Grant Co.], Oct., in fruit (991)." —Holotypus, collected by Charles Wright in 1851, GH! isotypus, NY!— Parosela polygonoides (Gray) A. Heller, Catal. N. Amer. Pl., ed. 2, 6. 1900.

    Dalea hutchinsoniae var. anomala Jones, Extr. from Contrib. West. Bot. 18: 42. 1933.—"Chiricahua mts., Ariz. in Rustlers’ Park, Sept 22 1931..." — Lectotypus (Morton, l.c. infra): Jones, s. n., POM no. 187431, POM!— D. polygonoides var. anomala (Jones) Morton, Contrib. U. S. Nat. Herb. 29: 102. 1945.

    Dalea polygonoides var. laevituba (smooth-tubed, of the externally glabrous calyx) Kearn. & Peeb., Jour. Wash. Acad. Sci. 29: 483. 1939.— "Type: Harrison, Kearney, & Fulton 8089, Santa Catalina Mountains, Pima County, Ariz., August 23, 1931..." — Holotypus, US!

    Within the known range of D. polygonoides there are only two annual daleas with persistent bracts that might be confused with it, D. exigua and D. confusa, both of which are distinguished by the presence of at least a few fine spiral hairs along the margins of the leaflets. A sympatric species with glabrous foliage, D. filiformis, has early deciduous bracts and truly filiform leaflets. At the south limit of its range in Durango D. polygonoides occurs within a few miles of the closely related D. thouini, like it in foliage but easily distinguished by the nigrescent bracts almost eglandular externally and white-silky inside.

    The species varies considerably in stature, the smallest individuals growing in poor stony soil being reduced sometimes to a single stem with one terminal flower-head while others, better nourished, become several times branched and many-headed. Exaggerated notice has been accorded the variant with glabrous calyx-tube, which occurs in the same population as the nomenclaturally typical form with externally pubescent calyx (cf. Barneby 5099, NY), and where segregated from this, has not acquired a distinctive or continuous range. I therefore list var. anomala and var. laevituba as exact synonyms.