3361 x 5042 px | 28,5 x 42,7 cm | 11,2 x 16,8 inches | 300dpi
Aufnahmedatum:
2007
Weitere Informationen:
Cockleburs belong to the enormous sunflower family (Asteraceae), the largest plant family with approximately 24, 000 species. The seeds are typically enclosed in a one-seeded fruit, called an achene, which is often airborne with a plume of silky hairs resembling a miniature parachute. In the cocklebur, the achenes are enclosed in a bur or involucre that is covered with hooked prickles. Another related hitchhiker in the sunflower family, called burdock (Arctium lappa), is equally adapted for clinging to animals and inanimate objects. Like the cocklebur, its hooked prickles are very difficult to remove from a shag carpet or sweater. Other hitchhikers, such as bur clover (Medicago hispida) and teasel (Dipsacus sativa) belong to the legume family (Fabaceae) and teasel family (Dipsacaceae). Teasel bristles are stiff enough to raise and straighten the nap on woolen cloth. The large, spiny heads of teasel were used in carding wool in early days. The heads were split and mounted on belts or rollers that moved over the cloth.
