Xanthisma gracile
Xanthisma gracile[1] is a species of annual flowering plant in the aster or sunflower family (Asteraceae) known by the common names slender goldenweed[2] and annual bristleweed.[3]
Xanthisma gracile | |
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Species: | X. gracile |
Binomial name | |
Xanthisma gracile (Nutt.) D.R.Morgan & R.L.Hartm. | |
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Range and habitat
It is native the southwestern United States and northern Mexico, where it grows in the deserts and plateaus.
Growth pattern
It is a bristly annual herb growing erect up to 45 cm tall.
Leaves and stems
The oval or oblong leaves are 1-3 cm long and divided into lobes or teeth tipped with bristles.
Flowers and fruit
The 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.
Genetics
X. gracile has extra chromosomes that do not have any functional genes (B chromosomes), and about which little is known.[3]
References
- Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. p. 314
- "Machaeranthera gracilis". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 26 June 2015.
- Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. 2013, p. 218