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spoonleaf rockcress

Habit Perennials; short- to long-lived; apomictic; caudex sometimes woody. Perennials; short- to long-lived; sexual; caudex usually not woody (rarely with persistent, crowded leaf bases).
Stems

usually 2–7 per caudex branch, arising from margin of rosette near ground surface, 0.5–2(–3) dm, densely pubescent proximally, trichomes simple and stalked, 2-rayed, 0.3–0.8 mm, glabrous distally.

simple or few to several per caudex branch, arising from center of rosette near ground surface, 1.5–3.5(–5) dm, densely pubescent proximally, trichomes simple mixed with short-stalked ones, 2-rayed, 0.3–0.7 mm.

Basal leaves

blade narrowly oblanceolate, 1–3 mm wide, margins entire, ciliate, trichomes to 1 mm, surfaces pubescent, trichomes stalked, 2–4-rayed, 0.3–0.8 mm.

blade narrowly oblanceolate, 1.5–3(–4) mm wide, margins entire, strongly ciliate at least along petiole, trichomes (simple), to 1 mm, surfaces glabrous or sparsely pubescent, trichomes simple and short-stalked, 2-rayed, 0.3–0.7 mm.

Cauline leaves

3–7(–10), not concealing stem;

blade auricles 0.2–1 mm, surfaces of distalmost leaves glabrous.

5–15(–20), often concealing stem proximally;

blade auricles 0.5–1.5 mm, surfaces of distalmost leaves usually glabrous.

Racemes

6–15-flowered, unbranched.

10–30-flowered, usually unbranched.

Flowers

ascending at anthesis;

sepals pubescent;

petals white or lavender, 5–7 × 1.5–2.5 mm, glabrous;

pollen spheroid.

divaricate-ascending at anthesis;

sepals pubescent;

petals usually white, rarely pale lavender, 3–3.7(–4) × 0.5–0.8 mm, glabrous;

pollen ellipsoid.

Fruiting pedicels

horizontal to divaricate-ascending, straight, 3–9 mm, glabrous.

horizontal or slightly descending, curved or angled downward, 6–10(–15) mm, usually glabrous, rarely sparsely pubescent, trichomes spreading, simple.

Fruits

horizontal to divaricate-ascending, not appressed to rachis, not secund, usually strongly curved, edges parallel, 3.5–6.5 cm × 1.7–2 mm;

valves glabrous;

ovules 50–84 per ovary;

style 0.05–0.5 mm.

pendent, not appressed to rachis, rarely slightly secund, straight or gently curved, edges parallel, 3.3–5.7 cm × 1.2–1.8 mm;

valves glabrous;

ovules 90–126 per ovary;

style 0.1–0.4 mm.

Seeds

uniseriate, 1.5–2 × 1.1–1.5 mm;

wing continuous, 0.1–0.2 mm wide.

biseriate, 0.7–0.9 × 0.5–0.6 mm;

wing distal or, sometimes, absent, 0.05–0.1 mm wide.

2n

= 14.

Boechera falcatoria

Boechera spatifolia

Phenology Flowering May–Jun. Flowering May–Aug.
Habitat Rock outcrops and gravelly soil in sagebrush and mountain shrub communities Rocky slopes and gravelly soil in sagebrush, pinyon-juniper woodlands, open conifer forests and subalpine meadows
Elevation 2000-2200 m (6600-7200 ft) 1800-2800 m (5900-9200 ft)
Distribution
from FNA
UT
[BONAP county map]
from FNA
CO; NM
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

Although the exact parentage of Boechera falcatoria, an apomictic hybrid, remains in doubt, it is virtually certain that B. cusickii contributed at least one genome. Boechera falcatoria has been confused with both B. pendulina and B. perennans, but is amply distinct from both (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). Despite the proximity of the type locality to both Idaho and Nevada, the species is known only from northwestern Box Elder County.

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

Boechera spatifolia is a sexual diploid that usually has been treated as a variety of Arabis (Boechera) fendleri but appears to be sufficiently distinct to warrant recognition at species level (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). There is little geographic overlap between the two, with B. spatifolia confined to the mountains of central Colorado and north-central New Mexico and B. fendleri ranging from western New Mexico and the Four Corners region through northern Arizona to southern Nevada.

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

Source FNA vol. 7, p. 376. FNA vol. 7, p. 408.
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. 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. 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. 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. stricta, B. subpinnatifida, B. suffrutescens, B. texana, B. tiehmii, B. tularensis, B. ultra-alsa, B. villosa, B. williamsii, B. xylopoda, B. yorkii
Synonyms Arabis falcatoria Arabis spatifolia, Arabis fendleri var. spatifolia, B. fendleri subsp. spatifolia, B. fendleri var. spatifolia
Name authority (Rollins) Dorn: Brittonia 55: 3. (2003) (Rydberg) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 84. (2006)
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