Ipomoea scopulorum Brandegee

Wood, John R. I., Munoz-Rodriguez, Pablo, Williams, Bethany R. M. & Scotland, Robert W., 2020, A foundation monograph of Ipomoea (Convolvulaceae) in the New World, PhytoKeys 143, pp. 1-823 : 1

135. Ipomoea scopulorum Brandegee , Zoë 5: 169. 1903. (Brandegee 1903-05: 169)

Ipomoea rhomboidea House , Ann. New York Acad. Sci. 18: 245. 1908. (House 1908b: 245).

Type.

MEXICO. Sinaloa, Tapolobampo, E. Palmer 227 (holotype US00111455, isotypes ARIZ, C, MICH, P, RSA, S).

Type.

MEXICO. Baja California Sur, Cape region, T.S. Brandegee s.n. (holotype UC105176).

Description.

Grey prostrate or twining perennial to 2 m, stems subglabrous, pubescent to subtomentose. Leaves petiolate, variable in form, 2-8 × 1.5-7.5 cm, ovate-deltoid, acute, cordate to truncate and cuneate onto the petiole, often shallowly 3-lobed, sometimes deeply 3-lobed with suborbicular to rhomboid lobes that are contracted below, margin somewhat undulate, both surfaces thinly to densely pubescent with simple and branched hairs, especially on the veins; petioles 1-6 cm, nearly glabrous to pubescent. Inflorescence of lax 1-5-flowered cymes; peduncles 1-3.8 cm, pubescent; bracteoles 1-1.5 mm, filiform, caducous; pedicels 15-35 mm, sometimes winged, pubescent; sepals slightly unequal, somewhat coriaceous, outer sepals 5-8 × 3-4 mm, oblong to oblong-elliptic, obtuse, mucronulate, pubescent, the margins scarious, glabrous, inner 9-13 × 6-7 mm, broadly obovate-elliptic, rounded, mucronulate, scarious except for central area; corolla 6-9 cm long, narrowly funnel-shaped, glabrous, white with bluish centre, limb 6-8 cm diam., midpetaline bands ending in a mucro; anthers usually included. Capsules 10 × 10 mm, subglobose, rostrate, glabrous; seeds 7 mm, densely pilose on the margins with hairs to 8 mm.

Illustration.

Figure 80 .

Distribution.

Growing amongst rocks at low altitudes in northwestern Mexico.

MEXICO. Baja California Sur: T.S. Brandegee s.n. [11/10/1904] (GH); Rancho La Burrera, M. Domínguez 311 (IEB). Nayarit: Presa Aguamilpa, J.I. Calzada et al. 18610 (MEXU), 18633 (MEXU). Sinaloa: Mazatlán, T.S. Brandegee s.n. [8/10/1893] (MEXU); ibid., Ynés Mejia 48 (MO); Culiacán, Cerro Piedrera, M. Provance 9616 (MO, UCR); Presa El Comedero, R. Vega Aviña et al. 6098 (MEXU); Sierra de Tacuichamona, R. Vega Aviña et al. 6698 (MEXU). Sonora: San Bernardo, Río Mayo, H.S. Gentry 1574 (ARIZ, F, K, MEXU, MO, S); (ARIZ); Mun. Soyopa, Río Yaqui, M. Fishbein et al. 3573 (ARIZ, MO); Mun. Sahuaripa, A.L. Reina-G et al. 2003-937 (ARIZ).

Typification.

The specimen of Ipomoea scopulorum at MEXU (00025258) is a paratype, not an isotype as labelled.

Note.

This species is rather variable in leaf size and shape, indumentum and corolla size. Entire leaves are deltoid and basally truncate, but the deeply 3-lobed leaves have the terminal leaflet somewhat rhomboid in form. The indumentum is quite variable in its density and the branched hairs are not easily discerned even with a microscope.

Figures

Figure 80. Ipomoea scopulorum. A habit B abaxial leaf surface C inflorescence with bud D outer sepal E middle sepal F inner sepal G corolla opened out to show stamens H ovary and style. Drawn by Rosemary Wise A, B from Gentry 1574; C-H from T. S. Brandegee s. n.