Ipomoea grandifolia (Dammer) O'Donell

Wood, J.R.I., Carine, M.A., Harris, D. et al. 2015. Ipomoea (Convolvulaceae) in Bolivia. Kew Bulletin 70: 31. DOI https://doi.org/10.1007/s12225-015-9592-7

Ecology

Ipomoea grandifolia is apparently frequent in NE Argentina, Paraguay and much of eastern Brazil whereas I. cordatotriloba, which also occurs in North America, is mostly found in the Andean foothills of Argentina and Bolivia but extends into Paraguay. There are few certain records from Bolivia, all from the eastern lowlands where it grows on disturbed grassy roadsides at low altitudes

Conservation

Not evaluated (NE) because of its uncertain taxonomic status.

Note

Ipomoea grandifolia was a forgotten species misplaced in Jacquemontia until it was transferred into Ipomoea and rediagnosed by O’Donell (1952: 226 – 228). Comparing his summary of its characteristics in 1952 with that in his posthumous account of Ipomoea in Argentina (1959b) O’Donell had clearly come to depend on flower size alone to distinguish I. grandifolia, rather than any of the secondary characters discussed in 1952. However, flower size is scarcely a satisfactory character given the range of variation in corolla size within I. cordatotriloba. Examination of the surviving isotype of Ipomoea grandifolia at Kew shows a plant with a corolla 2 – 2.2 cm long and narrowly ovate outer sepals which taper to a mucronate apex. This is a near perfect match for Wood & Williams 27733 from Ivirgazama in Cochabamba Department. Unfortunately the narrower sepals are no more convincing as a character than the corolla size as many specimens of I. cordatotriloba have similar sepals, rather than the more usual ovate, more abruptly mucronate sepals often found in that species.Ipomoea grandifolia appears to be a small-flowered variant of I. cordatotriloba with no distinct ecology. In the greenhouses of the International Potato Centre in Lima, there are numerous living plants of both species grown from collections from Paraguay, Argentina and Bolivia. These show a baffling range of corolla size and capsule indumentum and supposed differences between the species are totally unconvincing.Ipomoea grandifolia is also very close to the widespread I. triloba L., which is absent from South America according to Austin (1978) and Austin & Huáman (1996), although widely distributed as a weed in the Old World. Austin (1978: 120) claims I. grandifolia is a hybrid but only suggests I. cordatotriloba as one parent. Perhaps it has arisen as a result of hybridisation with an introduced I. triloba resulting in offspring showing a range of corolla sizes, sepal shape and indumentum that bridges the two species. This problem is only likely to be resolved by detailed molecular studies using a very large sample.

Flowers at the end of the rainy season from February to July. This is distinguished from Ipomoea cordatotrilobata by the shorter corolla (1.5 – 2.5 cm long).

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident