Al Schneider's Rocky Mountains Plant Descriptions

Crownleaf Evening Primrose
Oenothera coronopifolia
Evening-Primrose family (Onagraceae)

The very finely cut leaves, large white flowers, and spreading clusters of this slender Oenothera distinguish it. Oenothera coronopifolia often grows in colonies of many plants; areas of the foothills would have this as a common plant if it were not for cows, alfalfa fields, and lawn mowers. "Coronopifolia" means "having leaves like the Mustard, Coronopus." The plant was first collected by Edwin James in 1820 near the forks of the Platte River and was described by Torrey and Gray in their 1840 "Flora of North America.


©2009 Barry Breckling

Description

from spreading rootstock or , mainly 4-24" tall. Stems or branched at ground level. Herbage hairy. Leaves mainly on stem, 1/2 to 3 inches long and up to 3/4" wide, deeply . Flowers solitary in upper axils, nodding in bud. to almost 1" long. Petals white, fading pink or white, form 2/5 to nearly 1 inch long. . erect .

Field Marks

Short plant, often in colonies, with very finely cut leaves and large white flowers.

© Al Schneider

style -- This is a long and thread-like structure that connects the stigma with the ovary. A flower may have a single style, or several of them.

A perennial plant lives and blooms for many years.

pinnatifid -- A leaf shape that is pinnately lobed but not cut all the way to the axis.

A herb is a plant whose stems die back to the ground in the winter.

Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom.

taproot -- The primary decending root of a plant.

capsule -- a type of simple, dry fruit produced by many species of flowering plants. In most cases the capsule splits apart to release seeds.

fruit -- any seed-bearing structure in flowering plants. It is formed from the ovary after flowering.

A simple leaf blade is one that is not divided into separate leaflets.

exserted -- projected beyond. (Exserted stamens project beyond the corolla tube.)