This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Climbing and extensively branching herbaceous vines, with alternate bipinnate or decompound leaves, and small axillary tendril-bearing corymbs of slightly irregular polygamo-dioecious flowers. Tendrils 2 to each corymb, opposite. Pedicels jointed. Sepals 4, the 2 exterior smaller. Petals 4, 2 larger and 2 smaller. Disk I-sided, undulate. Stamens 8; filaments unequal. Ovary 3-celled; style short, 3-cleft; ovules 1 in each cavity. Capsule inflated, 3-lobed. Seeds arilled at the base; cotyledons conduplicate. [Greek, heart-seed.]
About 15 species, of warm and temperate regions, the following typical.
Cardiospermum Halicacabum L. Sp. Pl. 366. 1753.
Slender, glabrous or slightly pubescent, climbing, 2°-6° long. Leaves petioled, biternate or bipinnate, 2'-4' long; segments stalked, ovate or oblong, acute or acuminate, sharply serrate; peduncles commonly longer than the leaves, bearing a few-flowered corymb at the summit; flowers white, 3"-4" broad; capsule much inflated, about 1' long, globose-pyriform; seeds globose, nearly black.
In waste places, New Brunswick, N. J., Washington, D. C, Kansas, and in ballast about the sea-ports; common in cultivation. Native of tropical America, and widely diffused as a weed in the warmer parts of the Old World. Heart-pea. Winter-cherry. Puff-ball. Summer.
Koelreuteria paniculáta Laxm., a Chinese tree with pinnate leaves and terminal panicles of yellow flowers succeeded by 3-lobed bladery pods, is much planted for shade and ornament and is reported spontaneous from seed in Indiana.