Arnica discoidea

Taxobox
name = "Arnica discoidea"


regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Asterales
familia = Asteraceae
tribus = Heliantheae
genus = "Arnica"
species = "A. discoidea"
binomial = "Arnica discoidea"
binomial_authority = Benth.
synonyms = "Arnica grayi"
"Arnica parviflora"

"Arnica discoidea" is a species of arnica known by the common name rayless arnica. It is native to the woodlands, forests, and chaparral of the western United States. This is a rhizomatous perennial herb producing a hairy, glandular stem 20 to 60 centimeters tall. There are several pairs of toothed oval to spade-shaped leaves on long petioles around the lower half of the stem. The inflorescence contains a few to many flower heads which are coated with glandular hairs. Each head contains only disc florets, but some of the florets around the edge can be expanded and resemble ray florets, making identification of the plant by its flower difficult. The fruit is an achene about 7 millimeters long, not counting its light-colored pappus.

External links

* [http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?609,701,706 Jepson Manual Treatment]
* [http://plants.usda.gov/java/profile?symbol=ARDI6 USDA Plants Profile]
* [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066112 Flora of North America]
* [http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_index&where-taxon=Arnica+discoidea Photo gallery]