Erysimum capitatum (Western wallflower)

Erysimum capitatum (Douglas ex Hook.) Greene

Western wallflower, sanddune wallflower

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Rosidae	Roses, legumes, proteas, dogwoods, hydrangeas, mistletoes, euphorbias, grapes, many more
Order	Brassicales	Mustard, cabbage, caper, papaya, nasturtiums, many others; most produce mustard oil
Family	Brassicaceae	Mustards, cabbages
Genus	Erysimum	From the Greek eryomai, “to help or save,” because some of the species supposedly had a medicinal value
Species	capitatum	Capitate, refers to the way the flowers form in a head-like cluster

About plant names...

Coastal wallflower is native to North America. It is a member of the very large mustard family.

Identification: Plants are 12-48" (30-121 cm) tall, often with a single stem, sometimes with a few branches. Stems are coated with grayish hairs lying parallel against the stem. There is a basal rosette of many narrow leaves with variable shape and size, smooth-edged or toothed, 1-4½" (3-12 cm) × ¹/₁₆-⅜" (2-10 mm). Narrow leaves also appear sparsely along the stem. Flowers have four flat petals, and are 1-1¾" (3-5 cm) in diameter. They are yellow to deep orange, sometimes purplish-maroon or white; appearing from March to August. Fruits are upward-pointing pods 1-4" (3-10 cm) long and about ¹/₃₂" (1.5 mm) wide, four-sided.

Online References:

Erysimum capitatum on Missouriplants.com

Erysimum capitatum at Southeastern Arizona Wildflowers and the Plants of the Sonoran Desert

Erysimum capitatum on the USDA Plants Database

Erysimum capitatum on Wikipedia

Erysimum capitatum on Wildflowers, Ferns & Trees of Colorado, New Mexico, Arizona, and Utah

Erysimum capitatum on CalPhotos

Erysimum capitatum on Montana Plant Life

Erysimum capitatum on Turner Photographics' Wildflowers site

Erysimum capitatum on Eastern Colorado Wildflowers

Erysimum capitatum on SEINet—the Southwest Environmental Information Network

Erysimum capitatum from the Jepson Manual

Erysimum capitatum description by Thomas H. Kent, last updated 25 May 2020.

5/22/2009 · Slide Rock State Park, Sedona, Arizona
≈ 7 × 9" (17 × 23 cm) ID is uncertain

5/22/2009 · Slide Rock State Park, Sedona, Arizona
≈ 5 × 6" (13 × 14 cm) ID is uncertain

Range: Zones 3-7:

About this map...