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Cascade rock-cress, Cascade suncress, Cascades rockcress, littleleaf rockcress

dwarf rockcress, Parish's Rock cress

Habit Perennials; long-lived; (cespitose); apomictic; caudex somewhat woody. Perennials; short- to long-lived; sexual; caudex often woody.
Stems

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.

usually 1 per caudex branch, arising from center of rosette near ground surface, 0.3–1.4 dm, densely pubescent proximally, trichomes short-stalked, 2–8-rayed, 0.2–0.4 mm, sparsely pubescent distally.

Basal leaves

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.

blade linear to linear-oblanceolate, 0.5–2 mm wide, margins entire, often ciliate along petiole, trichomes (branched), to 0.6 mm, surfaces densely pubescent, trichomes short-stalked, 6–12-rayed, 0.07–0.15 mm.

Cauline leaves

4–6, not concealing stem;

blade auricles 0.5–1 mm, surfaces of distalmost leaves glabrous.

2–8, rarely concealing stem proximally;

blade auricles absent, surfaces of distalmost leaves densely pubescent.

Racemes

3–11-flowered, unbranched.

5–20-flowered, unbranched.

Flowers

ascending at anthesis;

sepals glabrous or sparsely pubescent;

petals lavender, 5–6 × 1–1.7 mm, glabrous;

pollen spheroid.

ascending at anthesis;

sepals pubescent;

petals lavender to purple, 8–13 × 2.5–4 mm, glabrous;

pollen ellipsoid.

Fruiting pedicels

ascending to divaricate-ascending, straight, 3–8 mm, glabrous.

ascending, straight, 3–7 mm, pubescent, trichomes appressed, branched.

Fruits

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.

ascending, not appressed to rachis, not secund, straight, edges parallel, 1.5–2.5 cm × 1.8–2.5 mm;

valves glabrous;

ovules 12–20 per ovary;

style 3–8 mm.

Seeds

uniseriate, 1.1–1.3 × 0.9–1 mm;

wing continuous, 0.05–0.1 mm wide.

uniseriate, 1.5–2 × 1–1.5 mm;

wing distal or continuous, 0.05–0.2 mm wide.

2n

= 14.

Boechera cascadensis

Boechera parishii

Phenology Flowering Jun. Flowering Mar–May.
Habitat Basaltic cliffs and rocky slopes in subalpine areas Gravelly hillsides in sagebrush- juniper-pine areas
Elevation ca. 1900 m (ca. 6200 ft) 1900-2300 m (6200-7500 ft)
Distribution
from FNA
OR; WA
[BONAP county map]
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Of conservation concern.

Boechera parishii is a distinctive, long-styled, sexual diploid known only from San Bernardino Mountains in San Bernardino County.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 7, p. 369. FNA vol. 7, p. 393.
Parent taxa Brassicaceae > tribe Boechereae > Boechera Brassicaceae > tribe Boechereae > Boechera
Sibling taxa
B. acutina, B. arcuata, B. atrorubens, B. bodiensis, B. breweri, B. burkii, B. calderi, B. californica, B. canadensis, B. cobrensis, B. collinsii, B. consanguinea, B. constancei, B. covillei, B. crandallii, B. cusickii, B. davidsonii, B. dentata, B. depauperata, B. dispar, B. divaricarpa, B. drepanoloba, B. duchesnensis, B. elkoensis, B. evadens, B. falcatoria, B. falcifructa, B. fecunda, B. fendleri, B. fernaldiana, B. formosa, B. fructicosa, B. glareosa, B. glaucovalvula, B. goodrichii, B. gracilenta, B. gracilipes, B. grahamii, B. gunnisoniana, B. harrisonii, B. hastatula, B. hoffmannii, B. holboellii, B. horizontalis, B. howellii, B. inyoensis, B. johnstonii, B. koehleri, B. laevigata, B. languida, B. lasiocarpa, B. lemmonii, B. lignifera, B. lincolnensis, B. lyallii, B. macounii, B. microphylla, B. missouriensis, B. nevadensis, B. ophira, B. oxylobula, B. paddoensis, B. pallidifolia, B. parishii, B. pauciflora, B. paupercula, B. peirsonii, B. pendulina, B. pendulocarpa, B. perennans, B. perstellata, B. pinetorum, B. pinzliae, B. platysperma, B. polyantha, B. porphyrea, B. pratincola, B. puberula, B. pulchra, B. pusilla, B. pygmaea, B. quebecensis, B. rectissima, B. repanda, B. retrofracta, B. rigidissima, B. rollei, B. rollinsiorum, B. rubicundula, B. saximontana, B. schistacea, B. serotina, B. serpenticola, B. shevockii, B. shockleyi, B. sparsiflora, B. spatifolia, B. stricta, B. subpinnatifida, B. suffrutescens, B. texana, B. tiehmii, B. tularensis, B. ultra-alsa, B. villosa, B. williamsii, B. xylopoda, B. yorkii
B. acutina, B. arcuata, B. atrorubens, B. bodiensis, B. breweri, B. burkii, B. calderi, B. californica, B. canadensis, B. cascadensis, B. cobrensis, B. collinsii, B. consanguinea, B. constancei, B. covillei, B. crandallii, B. cusickii, B. davidsonii, B. dentata, B. depauperata, B. dispar, B. divaricarpa, B. drepanoloba, B. duchesnensis, B. elkoensis, B. evadens, B. falcatoria, B. falcifructa, B. fecunda, B. fendleri, B. fernaldiana, B. formosa, B. fructicosa, B. glareosa, B. glaucovalvula, B. goodrichii, B. gracilenta, B. gracilipes, B. grahamii, B. gunnisoniana, B. harrisonii, B. hastatula, B. hoffmannii, B. holboellii, B. horizontalis, B. howellii, B. inyoensis, B. johnstonii, B. koehleri, B. laevigata, B. languida, B. lasiocarpa, B. lemmonii, B. lignifera, B. lincolnensis, B. lyallii, B. macounii, B. microphylla, B. missouriensis, B. nevadensis, B. ophira, B. oxylobula, B. paddoensis, B. pallidifolia, B. pauciflora, B. paupercula, B. peirsonii, B. pendulina, B. pendulocarpa, B. perennans, B. perstellata, B. pinetorum, B. pinzliae, B. platysperma, B. polyantha, B. porphyrea, B. pratincola, B. puberula, B. pulchra, B. pusilla, B. pygmaea, B. quebecensis, B. rectissima, B. repanda, B. retrofracta, B. rigidissima, B. rollei, B. rollinsiorum, B. rubicundula, B. saximontana, B. schistacea, B. serotina, B. serpenticola, B. shevockii, B. shockleyi, B. sparsiflora, B. spatifolia, B. stricta, B. subpinnatifida, B. suffrutescens, B. texana, B. tiehmii, B. tularensis, B. ultra-alsa, B. villosa, B. williamsii, B. xylopoda, B. yorkii
Synonyms Arabis microphylla var. thompsonii Arabis parishii
Name authority Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 260. (2007) (S. Watson) Al-Shehbaz: Novon 13: 388. (2003)
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