Flora of the Hawaiian Islands
Dicotyledon Literature for Ipomoea batatas
Wagner et al., 1990, 1999; Lorence & Wagner, 2020.
   Convolvulaceae -- The Dodder, Morning Glory Family Bibliography
      Ipomoea batatas

Common name(s): morning glory, `uala, `uwala, sweet potato
General Information
DistributionPantropical, but of American origin, widely cultivated for its tubers. A Polynesian introduction on many Pacific islands.In the Hawaiian Islands, a Polynesian introduction on Midway, Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Kaho`olawe, Hawai`i.

Vine; stems erect, procumbent, or occasionally twining, often rooting at the nodes, usually somewhat succulent, but sometimes slender and herbaceous, to 4 m or more long, but often shorter in cultivars, glabrous or pubescent, from a tuberous root.
Leaves petiolate; blade, variable in shape and color, chartaceous to fleshy, cordate to ovate, 5‒10(‒15) cm long, glabrous or pubescent, entire or dentate to often deeply (3‒)5‒7-lobed, apex acute, base cordate to truncate.
Inflorescences a cyme, 1- to few-flowered, or apparently absent in some varieties, if present, glabrous or pubescent. Flowers on pedicel 3‒12 mm long; sepals chartaceous to slightly fleshy, unequal, outer 2 shorter than inner ones, oblong-lanceolate to oblong, (8‒)10‒15 mm long, glabrous or pubescent, but margin conspiculously ciliate with hairs to 1 mm long, especially toward the base, apex acuminate and cuspidate; corolla lavender to purple, white in some varieties, throat darker purple, funnelform, 4‒7 cm long; staminal filaments glabrous except at base.
Fruit rarely formed, brown, ovoid, sparsely pubescent, becoming glabrate.
Seeds 0‒1(‒4), orbicular, glabrous or with wings of short hairs.
2n = 84, 90.
Some collections of naturalized plants previously identified as I. batatas actually represent I. tiliacea (including Dunn & Lorence 470, Perlman 19029, and Wood 10781). These 2 species are separable by the differences given in the key.
Nancy Khan