Boechera villosa |
Boechera cascadensis |
|
---|---|---|
|
Cascade rock-cress, Cascade suncress, Cascades rockcress, littleleaf rockcress |
|
Habit | Perennials; short-lived; sexual; caudex not woody. | Perennials; long-lived; (cespitose); apomictic; caudex somewhat woody. |
Stems | 1–3 per caudex branch, arising laterally proximal to sterile shoots near ground surface, ca. 2.5 dm, densely pubescent proximally, trichomes simple and 2-rayed, 0.25–0.7 mm, glabrescent distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, 0.5–2.2 dm, sparsely pubescent proximally, trichomes simple and short-stalked, 2- or 3-rayed, 0.1–0.2 mm, glabrous distally. |
Basal leaves | blade oblanceolate to obovate, 2.5–5 mm wide, margins entire, ciliate along petiole, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes simple and short-stalked, 2- or 3-rayed, 0.25–0.5 mm. |
blade linear-oblanceolate, 0.7–2 mm wide, margins entire, ciliate proximally, trichomes to 0.4 mm, surfaces densely pubescent, trichomes short-stalked, (2- or) 3–6-rayed, 0.05–0.2(–0.3) mm. |
Cauline leaves | 4–6, not concealing stem; blade auricles ca. 1 mm, surfaces of distalmost leaves sparsely pubescent. |
4–6, not concealing stem; blade auricles 0.5–1 mm, surfaces of distalmost leaves glabrous. |
Racemes | 6–10-flowered, unbranched. |
3–11-flowered, unbranched. |
Flowers | ascending at anthesis; sepals pubescent; petals lavender, 4–5 × 1–1.5 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals glabrous or sparsely pubescent; petals lavender, 5–6 × 1–1.7 mm, glabrous; pollen spheroid. |
Fruiting pedicels | ascending, straight, 6–10 mm, glabrous or sparsely pubescent, trichomes subappressed, branched. |
ascending to divaricate-ascending, straight, 3–8 mm, glabrous. |
Fruits | divaricate-ascending, not appressed to rachis, not secund, slightly curved, edges parallel, 4–5 cm × ca. 1 mm; valves glabrous; ovules ca. 64 per ovary; style ca. 0.2 mm. |
ascending to divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 3.5–6.2 cm × 1.2–1.5 mm; valves glabrous; ovules 58–80 per ovary; style 0.8–1.5 mm. |
Seeds | uniseriate, (none mature). |
uniseriate, 1.1–1.3 × 0.9–1 mm; wing continuous, 0.05–0.1 mm wide. |
Boechera villosa |
Boechera cascadensis |
|
Phenology | Flowering May. | Flowering Jun. |
Habitat | Basalt outcrop in pinyon-juniper woodlands | Basaltic cliffs and rocky slopes in subalpine areas |
Elevation | ca. 2100 m (ca. 6900 ft) | ca. 1900 m (ca. 6200 ft) |
Distribution |
NM |
OR; WA |
Discussion | Boechera villosa is known only from the type collection from the Rio Grande Gorge in Taos County. The holotype was originally identified as Arabis (Boechera) perennans but clearly is more closely related to B. pallidifolia (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Morphological evidence suggests that Boechera cascadensis is an apomictic species that arose through hybridization between B. microphylla and B. paupercula (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). It is known from two collections: the type specimens from Kittitas County, Washington, and a more recent collection from Baker County, Oregon. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 411. | FNA vol. 7, p. 369. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis microphylla var. thompsonii | |
Name authority | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 86. (2006) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 260. (2007) |
Web links |
|