Though the black-eyed Susan vine, Thunbergia alata, has similar verve and delicate foliage, its abundant flowers are much more dramatic. A good 2 to 3 inches across, they are a cheerful yellow-orange that stands out against the leaves. The “black eyes” are really rich chocolate-brown throats. I think of cup-and-saucer vine, Cobaea scandens, as an annual counterpart to wisteria — not because their flowers look alike (cobaea’s purplish blossom is a puffy 2-inch cup resting on a little saucer), but because both have large, compound leaves and grow with amazing speed: In my garden, cobaea clambers to the top of an old pear tree in a single season. Spanish flag, Ipomoea lobata (Mina lobata), is in the morning-glory family, though you’d never guess it from the flowers: Small and tubular, they stay open all day. Flower buds fade from scarlet to yellow, Spain’s national colors. When fully open, the bloom is creamy white. In flower from midsummer till frost, I. lobata shares its morning-glory kin’s zest for climbing practically any support.