from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See trillium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Trillium erectum, a perennial plant of North America with deep-red flowers.
from the GNU version of the Collaborative International Dictionary of English
- n. An herbaceous plant (Trillium erectum), and its astringent rootstock, which is said to have medicinal properties.
from The Century Dictionary and Cyclopedia
- n. In botany, a name given to various species of Trillium, especially T. pendulum, the roots of which are reputed to be astringent, tonic, and alterative, and to have a special effect upon the uterus and connected organs. Also called birthwort, and corruptly bethroot and bathwort.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. trillium of eastern North America having malodorous pink to purple flowers and an astringent root used in folk medicine especially to ease childbirth
birth + root (Wiktionary)
So far the comments haven't mentioned the *other* lambs-quarters, Trillium erectum, also known colloquially as bethroot, birthroot, wakerobin, Indian balm, Indian shamrock, squaw root, and ground lily.