Xanthisma gracile

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Xanthisma gracile
Scientific classification
Kingdom:
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Order:
Family:
Genus:
Species:
X. gracile
Binomial name
Xanthisma gracile
(Nutt.) D.R.Morgan & R.L.Hartm.
Synonyms
  • Haplopappus gracilis
  • Machaeranthera gracilis

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]

Range and habitat[edit]

It is native the southwestern United States and northern Mexico, where it grows in the deserts and plateaus.

Growth pattern[edit]

It is a bristly annual herb growing erect up to 45 cm tall.

Leaves and stems[edit]

The oval or oblong leaves are 1-3 cm long and divided into lobes or teeth tipped with bristles.

Flowers and fruit[edit]

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[edit]

X. gracile has extra chromosomes that do not have any functional genes (B chromosomes), and about which little is known.[3]

References[edit]

  1. ^ Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. p. 314
  2. ^ "Machaeranthera gracilis". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 26 June 2015.
  3. ^ a b Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. 2013, p. 218

External links[edit]