Oenothera flava ssp. taraxacoides (Yellow evening primrose)

Oenothera flava (A. Nelson) Garrett ssp. taraxacoides (Wooton & Standl.) W.L. Wagner

Yellow evening primrose

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	Myrtales	Includes myrtles, leadwoods, loosestrifes, pomegranates, evening primroses, many others
Family	Onagraceae	Willowherb/evening primrose family
Genus	Oenothera	Derivation uncertain: 1. Greek ονος θηρας (onos theras), or “donkey catcher.” 2. Or οινος θηρας (oinos theras), “wine seeker.” 3. Or Latin oenothera, “a plant whose juices may cause sleep”
Species	flava	Latin for “yellow”
ssp.	taraxacoides	Means “like a dandelion”

About plant names...

This is the “dandelion subspecies” of yellow evening primose, so-called for the resemblance of its foliage to dandelion leaves.

Identification: You know you’re talking about an unusual plant when you can’t find much of anything about it online. Plants have a rosette of basal leaves reminiscent of dandelion leaves. Flowers emerge directly from the base on red stems. Flowers are yellow, about 1-1½" (2.5-3.8 cm) around, with four petals. Plants and flowers together are only about 8" (20 cm) tall.

Online References:

Oenothera flava ssp. taraxacoides on the USDA Plants Database

Oenothera flava on SEINet—the Southwest Environmental Information Network

Oenothera flava ssp. taraxacoides on Northern Arizona Flora

Oenothera flava at the Lady Bird Johnson Wildflower Center

Oenothera flava subspecies flava on Wildflowers, Ferns & Trees of Colorado, New Mexico, Arizona, and Utah

Lavauxia taraxacoides Wooton & Standl.

Oenothera taraxacoides (Wooton & Standl.) Munz

Lavauxia taraxacoides Wooton & Standl.

Oenothera taraxacoides (Wooton & Standl.) Munz

Lavauxia taraxacoides Woot. & Standl.

Oenothera taraxacoides (Woot. & Standl.) Munz