Xanthisma gracile
Xanthisma gracile[2] is a species of annual flowering plant in the aster or sunflower family (Asteraceae) known by the common names slender goldenweed[3] and annual bristleweed.[4]
| Xanthisma gracile | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Xanthisma |
| Species: | X. gracile |
| Binomial name | |
| Xanthisma gracile (Nutt.) D.R.Morgan & R.L.Hartm. | |
| Synonyms[1] | |
| |
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.[4]
References
- "Xanthisma gracile". Global Biodiversity Information Facility. Retrieved 3 July 2021.
- Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. p. 314
- USDA, NRCS (n.d.). "Machaeranthera gracilis". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 26 June 2015.
- Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. 2013, p. 218