Gaura glandulosa Wooton & Standley, Contr. U.S. Natl. Herb. 16: 153. 1913.

Wagner, Warren L., Krakos, Kyra N. & Hoch, Peter C., 2013, Taxonomic changes in Oenothera sections Gaura and Calylophus (Onagraceae), PhytoKeys 28, pp. 61-72 : 68

Gaura glandulosa Wooton & Standley, Contr. U.S. Natl. Herb. 16: 153. 1913.

Type.

United States. New Mexico: Catron County, Reserve, 9 July 1906, E. O. Wootons.n. (Holotype: US 561072!; Isotype: US!).

Annual herb from a stout taproot, usually well-branched at the base and above, 15-100 cm tall, villous proximally, the leaves subglabrous to densely short-villous, becoming subglabrous, strigillose and/or glandular puberulent distally. Leaves: rosette leaves lyrate, 3-15 × 0.5-1 cm; cauline leaves 1-9 × 0.1-0.8 cm, linear to very narrowly elliptic or narrowly lanceolate, sinuate-dentate to subentire, subsessile. Flowers 4-merous, opening at sunset; floral tube 6-10 mm; sepals 6-12 mm; petals 5.5-9.5 mm; filaments 4-6 mm, anthers 2-3 mm, pollen 90-100% fertile; style 11-18.5 mm. Capsule indehiscent, 6-8 × 2-3 mm, nut-like, hard, woody, not reflexed, broadly winged on the angles and deeply furrowed between the angles, the body ellipsoid or narrowly obovoid, narrowed at the base but not stipitate. Seeds 4, 2-3 mm, ovoid, usually flattened on one or several sides by crowding in the fruit, yellowish to reddish brown. Gametic chromosome number: n = 7. Self-compatible.

Phenology and distribution.

Flowering from (May) June to October. In Arizona from eastern Mohave County south through the mountains of central Arizona to eastern Pima County and the southwestern quarter of New Mexico, and in Mexico southward in the Sierra Madre Occidental to eastern Sonora and throughout the western halves of Chihuahua and Durango, often in disturbed sites in or on sandy washes, slopes, grasslands, meadows, pinyon-juniper or ponderosa pine woodlands, and sometimes on volcanic cinders; 760-2750 m.

Oenothera podocarpa is the first species to branch off in the subsect. Gaura clade ( Fig. 1 ), whereas Oenothera hexandra is nested well within the subsect. Gaura clade. The epithet “podocarpa” was selected among the three equally available names at the species rank for this species. Previously, Gaura gracilis , one of four species published simultaneously by Wooton and Standley,was selected by Munz (1938), while placing the other three into synonymy. Tidestrom and Kittell (1941) apparently unaware of the Munz publication selected Gaura glandulosa , but were incorrect as they should have used Gaura gracilis . They did not establish any new priority.

Figures

Figure 1. Portion of a Bayesian tree of Oenothera sect. Gaura within a larger analysis of one of two major clades of Oenothera, which has been referred to as clade B by Wagner et al. (2007) with several outgroup species of the other major clade (A) of Oenothera from Krakos et al. (unpubl.). The phylogeny is based on nuclear sequences of ITS and ETS and the chloroplast markers rps 16, ndh F, trn L-F, and rbcl. The labels use the most recent prior taxonomy, placing the group in Oenothera (Wagner et al. 2007), using the taxon delimitations of Raven and Gregory (1972). The taxa involved in the proposed changes here are in bold. Numbers above nodes indicate Bayesian posterior probability values.