This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Agrimonia gryposepala, Wallr. (Agrimonia hirsuta, Bieknell)
Native. Perennial. Propagates by seeds.
Time of bloom: June to August.
Seed-time: August to October.
Range: Nova Scotia and Maine to Minnesota, southward to North
Carolina. Also on the Pacific Coast. Habitat: Woodland borders, thickets along streams.
One of the many "stickseed" plants that vex the wool-grower, and rather common in the rocky brush-lot pastures usually given over to sheep. Stem two to four feet tall, slender, and covered with fine, spreading hairs. Roots fibrous and clustered. Leaves deep green, pinnatifid, mostly with seven - sometimes five or nine - large, coarsely toothed, oblong to obovate leaflets, and three pairs of smaller ones interposed between them; petioles hairy, with large, coarsely toothed stipules at the base. Flowers in long, slender, spicate racemes, the rachis glandular-hairy, interspersed with longer spreading hairs; blossoms less than a half-inch broad, with five small, rounded, yellow petals, many stamens, one pistil with two-parted style, and a hairy, five-lobed calyx, closed after flowering and surrounded with a ring of hooked bristles; these lengthen as the two achenes within mature, forming a small, top-shaped bur with its outer row of hooks de-flexed, the inner ones spreading and erect, so that no sheep or woollen garment can touch a spike without attaching most of its fruits. (Fig. 154.)
If flocks are to be kept in their neighborhood the plants should be searched out and closely cut while in first bloom. Or, when the ground is soft, they may be hand-pulled.
 
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