Ipomoea electrina D.F. Austin

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

294. Ipomoea electrina D.F. Austin & J.A. McDonald, Novon 12: 29. 2002. (Austin and McDonald 2002: 29)

Exogonium luteum House , Bull. Torrey Bot. Club 35: 103. 1908. (House 1908a: 103), non Ipomoea lutea Hemsl. (1879) . Type. MEXICO. Oaxaca, Cuesta de Chiquihuetlan, C. Conzatti & J. González 668 (holotype GH00054448, isotype NY).

Ipomoea woronovii var. lutea (House) D.F.Austin , Taxon 32: 626. 1983. (Austin 1983: 626).

Ipomoea shinnersii D.F. Austin , Ann. Missouri Bot. Gard. 64: 337. 1977 [pub. 1978]. (Austin 1978a: 337). Type. Based on Exogonium luteum House , nom. illeg. “woronowii” should have been used.

Ipomoea crocea McPherson ex Breedlove , Listados Floríst. México 4: 75. 1986. (Breedlove 1986: 75), nom. nud.

Type.

Based on Exogonium luteum House

Description.

Perennial herb to 3 m, stems woody below, pubescent. Leaves petiolate, 4-10 × 1.5-7 cm, ovate, finely acuminate, adaxially pubescent, abaxially tomentellous; petioles 1.5-3.5 cm. Inflorescence of axillary cymes of 3-18 flowers; peduncles 1.5-5 cm, pubescent; bracteoles linear-lanceolate, 5-10 × 1 mm, somewhat persistent; secondary peduncles 1-1.5 cm; pedicels 1.5-3 cm, pubescent; sepals unequal, coriaceous, often verrucose basally, glabrous or pubescent, outer 4-6 × 3-4 mm, ovate-deltoid, acute, inner 6.5-9.5 × 4-5 mm, oblong-elliptic, obtuse to rounded, scarious marginally; corolla 5-6.5 cm long, hypocrateriform, yellow or orange, glabrous except apically, the cylindrical tube 4-6 mm wide, the limb deeply lobed, the lobes linear-oblong 15-23 × 2 mm, being more deeply lobed and spreading when mature, the apex comose; stamens exserted 5-10 mm. Capsules conical; seeds dark brown, long-pubescent.

Illustration.

Figures 8D , 143 .

Distribution.

Endemic to southern Mexico, where it grows in dry deciduous oak forest between 700 and 2100 m.

MEXICO. Chiapas: D.E. Breedlove 27626 (MICH, MO). Oaxaca: Hac. Monserrate, C.A. Purpus 9189 (MO, US); Nejapa de Medero, E. Martínez Luis 332 (IEB); San Miguel Suchixtepec, P. Tenorio et al. 18410 (MEXU); Cerro Marimba, Tehuantepec, C. Martínez 1035 (MEXU).

Note.

In Flora Mesoamericana, Austin et al. (2012) treated Exogonium luteum as a synonym of Ipomoea urbinei without reference to I. electrina but this appears to have been an error. The two species are somewhat similar and have been confused, Ipomoea electrina sometimes being treated as a variety of I. urbinei (Austin 1983) . Ipomoea electrina is distinguished by the orange or yellow corolla with long linear-oblong, spreading lobes which are comose at the apex.

Figures

Figure 8. Corollas showing variations in form (side view), size, limb lobing and stamen exsertion. A Ipomoea argentea B I. repanda C I. neei D I. electrina E I. habeliana F I. santillanii G I. nationis H I. rubriflora J I. longistaminea K I. megapotamica L I. megalantha M I. neriifolia N I. syringifolia P I. ramosissima Q I. elongata R I. mucronatoproducta. A from Wood et al. 25639 and photo; B from Whitefoord 5244; C from Skutch 2043; D from Breedlove 27626; E from Bentley 203; F from Bourgeau 3024; G from Saunders 987; H from Wood et al. 27678; J from Pastore et al. 2678; K from Wood et al. 28060; L from Hassler 9114; M from Rezende et al. 1011; N from Stutz 1426 and photo; P from Bang 2246; Q from Purpus 3904; R from Wood & Villarroel 25474. Drawn by Rosemary Wise.

Figure 143. Ipomoea electrina. A habit B habit C abaxial leaf surface D outer sepal E inner sepal F corolla opened out to show stamens G ovary and style H flower showing less divided limb. Drawn by Rosemary Wise A-G from Breedlove 27626; H from Purpus 9189.