Arnica spathulata

{{Short description|Species of flowering plant}}

{{Speciesbox

|image = Klamath arnica imported from iNaturalist photo 134311138 on 10 September 2024.jpg

|genus = Arnica

|species = spathulata

|authority = Greene[http://plants.usda.gov/java/profile?symbol=ARSP4 USDA Plants Profile]

|synonyms_ref = [http://www.theplantlist.org/tpl1.1/record/gcc-3581 The Plant List Arnica spathulata Greene ]

|synonyms =

• Arnica cusickii Rydb.
• Arnica eastwoodiae Rydb.

}}

Arnica spathulata is a rare North American species of flowering plant in the family Asteraceae, known by the common name Klamath arnica.[http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?609,701,715 Jepson Manual Treatment] It is native to the Klamath Mountains of northwestern California (Humboldt, Trinity, Siskiyou, and Del Norte Counties) and southwestern Oregon (Curry, Josephine, Jackson, and Douglas Counties).[http://bonap.net/MapGallery/County/Arnica%20spathulata.png Biota of North America Program 2014 county distribution map] It grows in woodland habitat, almost exclusively on serpentine soils.[http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=693 Calflora taxon report, University of California, Arnica spathulata E. Greene, Klamath arnica ]

Arnica spathulata is a rhizomatous perennial herb producing one or more hairy, glandular stems 10 to 50 centimeters tall. There are several pairs of broadly lance-shaped leaves along the stem, and a cluster of leaves about the base of the stem. The basal leaves are up to about 15 centimeters long and the cauline leaves, those higher on the stem, are somewhat shorter.[https://www.biodiversitylibrary.org/item/52470#page/123/mode/1up Greene, Edward Lee 1896. Pittonia 3(15B): 103–104]

The inflorescence holds many flower heads lined with phyllaries coated in long, white hairs. The flower head is discoid, containing only yellow disc florets and none of the showier ray florets. The fruit is an achene up to a centimeter long, not counting its white pappus.[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066128 Flora of North America Vol. 21 Page 376 Klamath arnica Arnica spathulata Greene]