Echinocycystis contains both Latin and Greek roots that translate
roughly to "a sac with spines like a hedgehog," an appropriate description of the fruit.
Identification: These plants are herbaceous
vines, with tendrils that wrap around other plants and tighten to form a spring. They favor
wet ground—flood plains, river banks, borders of woods, thickets—anywhere with soggy
ground and lots of sun.
They contain alternate leaves, lobed and slightly serrated. The leaves are an off-center star, with two
small, two medium, and one longer point. Flowers are greenish-white, with six petals. They appear
from July to early August.
The fruits are the most interesting and unique aspect of these plants.
They are initially round and densely covered with soft prickles. They extend to a length of
1-1¾" (3-5 cm), variegated light/dark green, with prickles more spread out.
They have the shape and coloration of tiny watermelons, to which they are related.
In the fall the fruits, under accumulated hydrostatic pressure, open and eject their seeds, at a rather respectable speed of 38' (11 m) per second.
The empty shells, now light brown and looking a lot like a porcupine fish, often remain on
the plant through the winter. As the outer layer rots away, a netlike sac of fibers remains
to provoke the sense of wonder of passing naturalists (Photo 7).