Hemizonella is a genus of North American plants in the tribe Madieae within the family Asteraceae.[2][3]

Hemizonella
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Subfamily: Asteroideae
Tribe: Madieae
Subtribe: Madiinae
Genus: Hemizonella
(A.Gray) A.Gray
Species:
H. minima
Binomial name
Hemizonella minima
Synonyms[1]
  • Hemizonia § Hemizonella A. Gray
  • Hemizonia minima A.Gray
  • Harpaecarpus minimus (A.Gray) Greene
  • Melampodium minimum (A.Gray) M.E.Jones
  • Madia minima (A.Gray) D.D.Keck

The only known species is Hemizonella minima (opposite-leaved tarweed),[4] native to British Columbia, Washington, Oregon, California, Montana, Idaho, Nevada[5][6]

The plant grows in many types of forest, scrub, and chaparral habitats, from mountains to deserts. It is found in the Sierra Nevada and Cascade Range, and Mojave Desert.[3]

Hemizonella minima is a small annual herb producing a thin, fuzzy stem up to about 15 centimetres (5.9 in) in maximum height. The pointed, hairy leaves are no more than 2.5 centimetres (0.98 in) long. The inflorescence produces one or more tiny flower heads which are oblong or shaped like tops on close inspection. Each is a few millimeters wide, enclosed in phyllaries studded with stalked resin glands, and tipped with minute yellowish florets. The fruit is an achene a few millimeters long with no pappus.[3]

References edit

  1. ^ Tropicos, Hemizonella (A. Gray) A. Gray
  2. ^ Gray, Asa. 1874. Proceedings of the American Academy of Arts and Sciences 9: 189
  3. ^ a b c Flora of North America Vol. 21 Page 296, Hemizonella (A. Gray) A. Gray
  4. ^ USDA, NRCS (n.d.). "Hemizonella minima". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 14 May 2015.
  5. ^ Flann, C (ed) 2009+ Global Compositae Checklist
  6. ^ Hemizonella bonap