Ipomoea acutisepala O'Donell

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

20. Ipomoea acutisepala O'Donell , Lilloa 23: 478, 1950. ( O’Donell 1950b: 478)

Type.

ARGENTINA. Misiones, G.J. Schwarz 5098 (lectotype LIL001225, designated here; isolectotypes LIL, P).

Description.

Decumbent (rarely climbing) perennial with stems to 4 m long; stems thinly hispid. Leaves shortly petiolate, 5-11 × 1-10, elliptic to obovate in outline, 3-lobed to about halfway, base broadly cuneate, apex obtuse to rounded, strongly mucronate, both surfaces thinly to densely hispid; petioles 0.5-2.5 cm, hispid pilose. Inflorescence of long-pedunculate, compact axillary cymes with up to c. 8 flowers; peduncles 3-12 cm, hispid; bracteoles 5-15 × 0.5-1 mm, linear or lanceolate, acuminate, hispid, margins scarious; secondary peduncles very short or absent, up to 1 cm long; pedicels 3-8 mm, hispid; sepals subequal, 10-16 × 3-4 mm, lanceolate to ovate, finely acuminate, densely hispid-pilose; corolla 5.5-6.5 cm long, funnel-shaped, pink, pilose; limb c. 4 cm diam.; stigma bilobed with globose lobes. Capsules and seeds not seen.

Illustration.

Figure 22; O’Donell (1959b: 102).

Distribution.

Scattered over southern Brazil and neighbouring parts of Argentina and Paraguay.

ARGENTINA. Misiones: Dept. Candelaria, Rodríguez 1187 (CTES); Posadas, E.L. Ekman 1417 (LIL, S).

PARAGUAY. Itapúa: Trinidad, A. Krapovickas et al. 46153 (CTES, K).

BRAZIL. Paraná: A. Krapovickas & C. Cristóbal 39719 (CTES, FTG, K), 40802 (CTES, FTG); P. Dusen 2661 (S); Campo Largo, G. Hatschbach 3674 (US). Parque Iguaçu, L. R. Landrum 4045 (ARIZ, MO, NY); Jaguariaíva, T.B. Cavalcanti et al. 3675 (CEN); A. Krapovickas & A. Schinini 38237 (CTES); J.C. Lindeman & J.F.M. Valls 9502 (CTES, ICN); B. Rambo 34977 (S), 51633 (S). Santa Catarina: A. Krapovickas & C. Cristóbal 42007 (CTES, FTG), 43574 (CTES); L.B. Smith & R.M. Klein 8116 (S); L. B. Smith & R. Reitz 8632 (US), 9048 (MO, US); Mafra, R. Reitz 5370 (US). São Paulo: A. St. Hilaire 1525 (P).

Notes.

Similar to Ipomoea valenzulensis but the leaves are trifurcate and the inflorescence is many-flowered. It differs from Ipomoea langsdorffii in the trifurcate leaves, which are not whitish beneath, and from I. delphinioides in the finely acuminate sepals. Landrum 4045 has some leaves entire, some trifurcate.

O’Donell’s concept of this species contained elements of Ipomoea megalantha as he identified Hassler 9114 as I. acutisepala in 1953. Consequently, in the protologue he provided larger sepal and floral dimensions than are correct. The type (Schwarz 5098) itself is mostly 1-flowered and is not characteristic of the species.

P. Dusen 7385 (F, GH, MICH, P, S) from Serrinha, Paraná State is similar to Ipomoea acutisepala except for the subacute sepals. It is thus intermediate with I. delphinioides and has been identified with both species on different occasions.