Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
Pilea Lindl. -- Clearweed
Monoecious or dioecious, glabrous annuals; stems erect to decumbent,
simple or branched, rather brittle and watery, translucent; cystoliths appearing
as numerous minute, whitish or dark lines on the foliage of dried specimens.
Leaves simple, opposite; blades thin and translucent, ovate, with 3 major
veins arising from the base, broadly cuneate to rounded at the base, serrate,
the teeth prominent, obtuse to rounded, the terminal tooth short to elongate;
petioles subtending the inconspicuous, connate, membranous stipules. Flowers
greenish, clustered in axillary cymes; male flowers with 4 sepals and
4 stamens; female flowers with 3 sepals, these often unequal; staminodes
minute and scalelike; ovary superior, stigma sessile. Fruit a
flattened, ovate achene, subtended by the persistent calyx.
Fernald, M. L. 1938. Pilea in eastern North America. Rhodora 38:169-170.
||Achenes dark olivaceous to nearly black with a narrow
||Achenes green, often marked with purple.
10. Urticaceae, the Nettle Family
1. Pilea Lindl. -- Clearweed
- 1. Pilea fontana (Lunell) Rydb.
- 2. Pilea pumila (L.) A. Gray
Return to Family -- Urticaceae - The Nettle Family
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