Ipomoea tacuaremboensis Arechav.

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

362. Ipomoea tacuaremboensis Arechav. , Anales Mus. Nac. Montevideo 7: 195. 1911. (Arechavaleta y Balpardo 1911: 195)

Ipomoea tacuaremboensis forma foliosa Arechav., Anales Mus. Nac. Montevideo 7: 197 (1911). (Arechavaleta y Balpardo 1911: 197). Type. URUGUAY. Rivera, sine data (lectotype MVM, No. 1728 ex Herb. M.B. Berro, designated here).

Type.

URUGUAY. “Tacuarembó, Valle Edén, region Tambores, febrero", J. Arechavaleta 5483A (renumbered 458) (lectotype MVM, designated here).

Description.

Decumbent perennial, stems angled, muricate, glabrous, at least 50 cm long. Leaves shortly petiolate, 4-11 × 0.2-1(-2) cm, narrowly oblong or very narrowly lanceolate, acuminate and mucronate, base hastate to sagittate, glabrous; petioles 8-12 mm. Inflorescence of solitary, axillary flowers; peduncles 0-2 mm; bracteoles 3-6 mm, filiform; pedicels 5-12 mm; sepals unequal, glabrous; outer sepals 10-12 × 5 mm, oblong-ovate, acute, shortly mucronate, inner 15-19 × 8 mm, ovate, acuminate, mucronate, the apex often bent; corolla 5.5-7 cm long, pink, funnel-shaped, glabrous; limb c. 3 cm diam. Capsules 11 × 8 mm, ovoid with persistent style, glabrous; seeds tomentellous.

Distribution.

Apparently very rare in “campo”, presumably some kind of grassland in the border region of Uruguay and Brazil.

URUGUAY: Gruta de Las Cuervas, M.B. Berro 4823 (K).

BRAZIL. Rio Grande do Sul: 55 km W of Rosario do Sul, Krapovickas & Cristóbal 34234 (CTES, MO).

Lectotypification.

In selecting lectotypes, we have designated Arechavaleta 5483A as the lectotype of the type form as this is annotated by Arechavaleta as this species. The specimen designated as lectotype of forma foliosa is chosen because it appears to be the only possible specimen at MVM and is remarkable for the large number of leaves although there is no annotation to indicate Arechavalata considered it the type.

Note.

This species is sometimes treated as a synonym of Ipomoea kunthiana (Austin et al. 2015) but the leaves are different and we prefer to treat it as distinct for the time being. It is presumably related to Ipomoea paranaensis but is readily distinguished by the narrowly oblong leaves, muricate stems and very short peduncles.