Ipomoea

Identification key for Ipomoea species with white or blue corollas from the Borborema Plateau, Brazil 1. Branches, petioles, and peduncles with spine-like projections ............................................... 2 1. Branches, petioles, and peduncles without spine-like projections .................................... 3 2. Leaves with prominent veins on the abaxial surface; corolla white, glabrous .................... 4 2. Leaves without prominent veins on the abaxial surface; corolla blue with sericeous apex .......................................................... I. parasitica 3. Leaf blade entire; sepals with acute, obtuse to rounded apex; corolla white ......................... 5 3. Leaf blade trilobed; sepals with a long, caudate apex, hirsute at the base; corolla blue ..... I. nil 4. Corolla hypocrateriform; stamens exserted .. I. alba 4. Corolla campanulate; stamens inserted .. I. buriliae 5. Leaves pubescent to glabrescent; tubular corolla, white-greenish; stamens inserted .... I. vespertilia 5. Leaves velutinous; funnelform corolla, whiteyellowish; stamens inserted ........... I. marcellia