Xanthisma gracile
Xanthisma gracile[3] is a species of annual flowering plant in the family Asteraceae known by the common names slender goldenweed[4] and annual bristleweed.[5] Range and habitatIt is native the southwestern United States and northern Mexico, where it grows in the deserts and plateaus. Growth patternIt is a bristly annual herb growing erect up to 45 cm tall. Leaves and stemsThe oval or oblong leaves are 1–3 cm long and divided into lobes or teeth tipped with bristles. Flowers and fruitThe inflorescence bears one or more flower heads lined with pointed, roughly hairy phyllaries. The head has a center of many yellow disc florets and a fringe of 16 to 18 yellow ray florets roughly a centimeter long. The fruit is a woolly achene 2 to 3 millimeters long tipped with a pappus. GeneticsXanthisma gracile has extra chromosomes that do not have any functional genes (B chromosomes), and about which little is known.[5] Its chromosome count is given as 2n=4 by Munz and Keck.[6] References
External links
|
||||||||||||||||||||||||||||||||||||||
