Oenothera dodgeniana Krakos & W. L. Wagner, 2013

Wagner, Warren L., Krakos, Kyra N. & Hoch, Peter C., 2013, Taxonomic changes in Oenothera sections Gaura and Calylophus (Onagraceae), PhytoKeys 28, pp. 61-72 : 65-66

3. Oenothera dodgeniana Krakos & W. L. Wagner nom. nov.

Basionym.

Gaura neomexicana Wooton, Bull. Torrey Bot. Club 25: 307. 1898, non Oenothera neomexicana (Small) Munz (1931). Oenothera coloradensis (Rydberg) W. L. Wagner & Hoch subsp. neomexicana (Wooton) W. L. Wagner & Hoch, Syst. Bot. Monogr. 83: 211. 2007.

Type.

United States. New Mexico: Lincoln County, White Mts., 6500 ft, 25 Jul 1897, E. O. Wooton 204 (Holotype: US-330429!; Isotypes: AC!, E!, GH!, K!, LE, MIN, MO! ND, NY [2]!, P, US!).

Biennial from a stout fleshy taproot, with a single or a few branches from the base, 50-120 cm tall, villous and strigillose proximally, leaves subglabrous or strigillose, becoming also glandular puberulent distally, and sometimes also sparsely villous. Leaves: rosette leaves 6-20 × 1-3 cm; cauline leaves 5-10 × 1-2.5 cm, lanceolate to narrowly elliptic, subentire to repand-denticulate. Flowers 4-merous, opening at sunset; floral tube 10-11 mm; sepals 11-15 mm; petals 11-13.5 mm; staminal filaments 6.5-9 mm, anthers 2.5-4 mm long, pollen 90-100% fertile; style 22-28 mm. Capsule indehiscent, 9-11 × 3-5 mm, nut-like, hard, woody, not reflexed, the body ellipsoid or ovoid, sharply 4-angled, with fairly deep furrows alternating with the angles for 2-3 mm from the apex, ribbed from base of furrow to base of the fruit. Seeds 2-4, 2-3 mm, yellowish to light brown. Gametic chromosome number: n = 7. Self-compatible.

Phenology and distribution.

Flowering from June to September.In the western foothills of the San Juan Mountains in Archuleta County, Colorado, and Rio Arriba County, New Mexico; Sierra Blanca and Sacramento Mountains in Lincoln and Otero counties, south-central New Mexico. Collected once at Durango, La Plata County, Colorado ( Raven and Gregory 1972), but has not since been recollected; found in mountain meadow openings in coniferous forests; 1830-2640 m.

The new name for this species is to honor David and Judy Dodgen of Cloudcroft, New Mexico, landowners who graciously allowed one of us (Krakos) to conduct research on their land, which harbors populations of this rare species. Oenothera dodgeniana and Oenothera coloradensis were considered by Raven and Gregory (1972) to represent a relict species along the eastern flank of the Rocky Mountains that arose from more widespread species farther to the east, such as Oenothera filiformis . The new molecular analyses revealed that Oenothera coloradensis is closely related to Oenothera filiformis ( Fig. 1 ). Oenothera coloradensis is the first branch of a subclade within the subsect. Gaura clade that includes Oenothera filiformis and a terminal sister pair of Oenothera gaura and Oenothera simulans . These relationships suggest that Oenothera coloradensis may represent a relictual species and have a shared ancestry with Oenothera filiformis . Oenothera dodgeniana , on the other hand, belongs to a subclade which is sister to that containing Oenothera coloradensis , and within that subclade is sister to Oenothera demareei and Oenothera lindheimeri . So, although Oenothera dodgeniana is fairly closely related to Oenothera coloradensis , the two taxa seem to have had independent origins that have led to distributions along the eastern flank of the Rocky Mountains.

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.