Ipomoea platensis Ker-Gawl.

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

156. Ipomoea platensis Ker-Gawl. , Bot. Reg. 4: 333. 1818. (Ker-Gawler 1818d: 333)

Convolvulus platensis (Ker-Gawl.) Spreng., Syst. Veg. , ed. 16, 1: 591. 1825 [pub.1824]. (Sprengel 1824: 591).

Ipomoea digitata var. septempartita Meisn. in Martius et al. , Fl. Brasil. 7: 279. 1869. (Meisner 1869: 279) pro major parte, based partially on Ipomoea platensis Ker-Gawl.

Ipomoea lineariloba Peter, Nat. Pflanzenfam IV(3a): 30. 1897 [pub. 1891]. (Peter 1891: 30). Type. Cultivated in Göttingen from seeds thought to have come from Argentina (lectotype GOET005697, designated by Staples et al. 2012: 676.

Ipomoea platensis var. genuina Hassl. , Repert. Spec. Nov. Regni Veg. 9: 155. 1911. (Hassler 1911: 155), nom. illeg. Type. PARAGUAY. Gran Chaco, Santa Rita, Hassler 2448 (isotype MPU).

Ipomoea platensis var. quinquepartita Hassl. , Repert. Spec. Nov. Regni Veg. 9: 154. 1911. (Hassler 1911: 154). Type. PARAGUAY. Gran Chaco, K. Fiebrig “1340” [1240] (lectotype G00175089, designated here).

Ipomoea platensis forma subseptempartita [as var. quinquepartita forma subseptempartita] Hassl., Repert. Spec. Nov. Regni Veg. 9: 154. 1911. (Hassler 1911: 154). Type. PARAGUAY. Gran Chaco, Puerto Talavera, K. Fiebrig 1402 (lectotype G00175085, designated here; isolectotypes G).

Ipomoea platensis var. subnovempartita Hassl. , Repert. Spec. Nov. Regni Veg. 9: 155. 1911. (Hassler 1911: 155). Type. PARAGUAY. [ Boquerón /Presidente Hayes], Río Pilcomayo, T. Rojas 77 in Hassler (holotype G00175088).

Ipomoea platensis var. erecta Hassl. , Repert. Spec. Nov. Regni Veg. 9: 155. 1911. (Hassler 1911: 155). Type. not cited, PARAGUAY. [Presidente Hayes], west bank of Río Paraguay, Rojas in Hassler 2448a (lectotype G00175091, designated here; isolectotype BM).

Type.

Cultivated from seed sent by Cooper from the banks of the Río Plata, apparently not preserved, lectotype t. 433 of the Botanical Register 4 (1818), designated here.

Description.

Perennial with stout tuberous roots, stems glabrous, or, less commonly, pubescent, decumbent, erect or twining. Leaves petiolate, 2-8 × 2-9 cm, palmately 5-9-lobed nearly to the base, the lobes 20-55 × 2-10 mm, oblong-oblanceolate, obtuse or acute, margin entire to undulate, base truncate, both surfaces glabrous, abaxially paler; petioles 1-3.5 cm. Inflorescence of 1-7 flowers in pedunculate, axillary cymes; peduncles 1-4 (-13) cm, glabrous; bracteoles 3-4 mm, lanceolate, caducous; pedicels 5-15 mm, thickened upwards, glabrous; sepals 6-10 mm, slightly unequal, obovate to broadly elliptic, obtuse, glabrous, the inner suborbicular and with scarious margins; corolla 4.5-6 cm long, funnel-shaped, pink, glabrous, limb 4-5 cm diam., entire; stamens short. Capsules 7 × 8 mm, subglobose, glabrous, rostrate; seeds tomentose with longer hairs on margins.

Illustration.

Figures 83E, F ; 91 ; O’Donell (1959b: 215).

Distribution.

Essentially a plant of swampy areas principally along the Paraná-Pilcomayo river systems but also occurring in dry inter-Andean valleys at around 2000 m in Salta. URUGUAY. E. Gibert 176 (K); P. Favresse s.n. (P).

ARGENTINA. Chaco: Col. Benítez, A.G. Schulz 10989 (CTES), 18060 (CTES); La Paz, H. Keller 3914 (CTES). Corrientes: 12 km E de Colonia Pellegrini, Tressens et al. 3744 (CTES, K); Est. Santa María, T.M. Pedersen 3303 (C, K, S); Mercedes, J. Irigoyen & A. Schinini 159 (CTES, FTG). Entre Ríos: Victoria, E.K.A. Mari 730 (CTES). Federal: S. Venturi, 31 (S); Castellanos 31-1262 (CTES). Formosa: 3 km NW of Pirané, I. Morel s195 (S); 324 (K); Laishi Res. Ecol. El Bagual, A. di Giacpomo 377 (CTES). Salta: Valle de Lerma, Palaci 345 (MCNS).

PARAGUAY. Alto Paraguay: K. Fiebrig 1402 (K); Río Timané, R. Spichiger et al. 2506 (FCQ, G), 2793 (FCQ, G). Guairá: 15 km N of Tebicuary, E. Zardini & R, Velázquez 24088 (MO). Presidente Hayes: E. Zardini & Guerrero 41637 (FTG); Santa Asunción, J. de Egea et al. 192 (BM, FCQ).

BRAZIL. Paraná: Braga 44 (MBM).

Note.

This species is very variable in the number of leaf segments.We have received reports from Mario Giorgetti and seen photographs of this species growing between 2000 and 2500 m in the Calchaqui valley in Salta (Argentina), for example at Cerro Negro, Angastaco at 2060 m. This is at a much higher altitude and more arid habitat than is otherwise known for Ipomoea platensis and these populations merit further study. However, I. platensis develops very stout tuberous roots, which must be extremely drought-resistant and has long been cultivated successfully as a pot plant.

Figures

Figure 83. Ipomoea batatoides. A habit B outer sepal C inner sepal D corolla opened out to show stamens E base of stamen F ovary and style G fruiting inflorescence. Drawn by Rosemary Wise A-F from Colque & Mendoza 196; G from Santos 73.

Figure 91. Ipomoea platensis. A habit B habit with leaves C inflorescence and corolla D fruiting inflorescence with capsules E seed. Drawn by Rosemary Wise A, D, E from Spichiger et al. 2506; B from Spichiger et al. 2793; C from Fiebrig 1402.