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boechera paupercula, littleleaf rockcress, small-flower rock-cress, tiny suncress

spoonleaf rockcress

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

usually 1 per caudex branch, arising from center of rosette near ground surface, 0.3–1.5 dm, densely pubescent proximally, trichomes simple and short-stalked, 2–4-rayed, (0.07–)0.1–0.2 mm, glabrous or sparsely pubescent 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 linear-oblanceolate, 1–3(–5) mm wide, margins entire, ciliate proximally, trichomes to 0.4 mm, surfaces densely pubescent, trichomes short-stalked, 2–6-rayed, (0.07–)0.1–0.2 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

2–6, rarely concealing stem;

blade auricles 0 (or 0.2–1.5) 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

3–8-flowered, unbranched.

10–30-flowered, usually unbranched.

Flowers

erect at anthesis;

sepals glabrous or sparsely pubescent;

petals lavender to purplish, 4–6(–7) × 1–2 mm, glabrous;

pollen ellipsoid.

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

erect, straight, 3–9 mm, glabrous or sparsely pubescent.

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

Fruits

erect, appressed to rachis, not secund, straight, edges parallel, 2.5–5.5 cm × 1.3–1.7(–2) mm;

valves glabrous;

ovules 24–40 per ovary;

style 0.2–1 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

usually uniseriate, rarely sub-biseriate, 1.5–2(–2.5) × 1–1.4 mm;

wing continuous, 0.3–1 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 paupercula

Boechera spatifolia

Phenology Flowering Jun–Aug. Flowering May–Aug.
Habitat Rock outcrops, talus slopes, gravelly soil in alpine and subalpine habitats Rocky slopes and gravelly soil in sagebrush, pinyon-juniper woodlands, open conifer forests and subalpine meadows
Elevation 2400-3400 m (7900-11200 ft) 1800-2800 m (5900-9200 ft)
Distribution
from FNA
CA; ID; OR; WA; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; NM
[WildflowerSearch map]
[BONAP county map]
Discussion

Boechera paupercula is usually subsumed under Arabis (Boechera) lyallii but is amply distinct (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison).

(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. 394. 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. 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. 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 paupercula, Arabis lyallii var. nubigena, Arabis microphylla var. nubigena, Arabis nubigena Arabis spatifolia, Arabis fendleri var. spatifolia, B. fendleri subsp. spatifolia, B. fendleri var. spatifolia
Name authority (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 75. (2006) (Rydberg) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 84. (2006)
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