Ipomoea longifolia Benth.

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

93. Ipomoea longifolia Benth. , Pl. Hartweg. 16. 1839. (Bentham 1839-57: 16)

Convolvulus queretarensis Sesse & Mocino , Pl. Nov. Hisp. 1: 24. 1888. ( Sessé y Lacasta and Moçiño 1887-90: 24), Type. MEXICO. Querétaro, “Pavón” (isotype BM 000645558).

Type.

MEXICO. Zacatecas or Nuevo León, K.T. Hartweg 97 (holotype K000612741, isotypes BM, BR, E, GH. LD, NY, OXF, P).

Description.

Rhizomatous perennial with a stout woody base; stems decumbent to at least 1 m, herbaceous, glabrous. Leaves shortly petiolate, 8-18 × 0.5-4 cm, lanceolate or oblong-lanceolate, acuminate, base cuneate, glabrous; petioles 0.5-2 cm. Inflorescence of solitary (rarely paired), axillary flowers, peduncles 3-6(-16) cm; bracteoles c. 1 mm, elliptic, scarious, caducous; pedicels 13-21 mm; sepals very unequal, coriaceous, glabrous, margins scarious, outer 10-16 × 6-7 mm, oblong-elliptic, mucronate to retuse, inner 16-23 × 7-8 mm, obovate, rounded; corolla 6.5-11 cm long, funnel-shaped, white with pink throat, glabrous, limb 4-5 cm diam., lobed with apiculate lobes. Capsules 2 × 1.5 cm, ovoid, rostrate, the mucro 3-5 mm, glabrous; seeds 11 × 5 mm, black, glabrous but except for the pilose margins with hairs 3-4 mm long.

Illustration.

Carranza (2007: 66).

Distribution.

Desert grasslands and dry oak woodland in northern Mexico and the United States Southwest.

MEXICO. Aguascalientes: Asientos, al W. del Polvo, G. Garcia 4205 (IEB). Chihuahua: Urique, Kirare, P. Tenorio et al. 9944 (MO). Durango: E. Palmer 229 (BM, K); Victoria, F. Shreve 9169 (ARIZ). Guanajuato: Mun. San Miguel Allende, R.B. Brown 82-23 (ARIZ); San Felipe, R. & J.D. Galván 2260 (IEB), 2674 (IEB). Jalisco: Logas de Moreno, R. Pearce 2266 (ARIZ). Querétaro: 2 km N of El Sauz, R. Pearce 2245 (ARIZ); Matancillas, P. Carillo-Reyes et al. 509 (IEB). Sonora: Mun. Nacozari, R. Felger 3653 (ARIZ); Imuris, S. Doan et al. 1207 (ASU, DES). Zacatecas: NE Zacatecas, J. Henrickson 6665 (ARIZ); ibid., R.G. Engard & H.S. Gentry 705 (DES).

UNITED STATES. Arizona: Nogales, R.H. Peebles et al. 4613 (K); Cochise Co., Dragoon Mts, D & S. Austin 7582 (ARIZ). New Mexico: C. Wright 1617 (K).

Note.

Ipomoea longifolia might be confused with Ipomoea leptophylla but the sepals of I. longifolia are very unequal and much longer.

• The remaining species in Clade A1 (Species 94-127) include two distinct clades (Species 98-108 and 117-126) inferred from a combination of molecular sequence data and morphology. All species (94-127) have a tendency towards woodiness, most obvious in the Arborescens Clade (Species 117-126). Many, but not all, species have hirsute sepals, strongly discolorous leaves and a tendency to develop inflorescences on leafy axillary shoots.