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Physaria alpestris

alpine twin-pod, Washington bladder-pod, Washington twin-pod

Snake River or creeping twinpod, Snake River twinpod

Habit Perennials; caudex usually simple, rarely branched, (cespitose); (silvery) pubescent throughout, trichomes several-rayed, rays (1- or) 2-bifurcate, (low-umbonate, tubercles relatively few, small). Perennials; caudex usually branched, (rhizomelike, cespitose); densely (silvery) pubescent, trichomes (often stalked, appressed), several-rayed, rays furcate or bifurcate, (umbonate, strongly tuberculate throughout).
Stems

several from base, decumbent to ascending, (unbranched), 0.5–1.5 dm.

several from base, ± erect, exceeding basal rosette by ± 0.5 dm.

Basal leaves

(petiole slender);

blade obovate, 3–5 cm (width 10–20 mm, base tapering abruptly to petiole), margins entire, (apex rarely slightly acute).

(forming a strong rosette; long-petiolate);

blade oblanceolate to ovate or orbicular, (1.5–)2–4(–8) cm, (base usually abruptly tapering to petiole), margins entire.

Cauline leaves

blade oblanceolate, 0.5–1.5 cm (width 3–5 mm), margins entire.

blade oblanceolate, 1–2 cm, margin entire, (apex acute).

Racemes

subcorymbose.

congested, (greatly exceeding leaves).

Flowers

sepals oblong, 8–10 mm;

petals spatulate, 12–14 mm.

sepals often keeled, 6–8 mm;

petals spatulate, 8–10 mm.

Fruiting pedicels

(divaricate, straight), 5–10 mm.

(spreading, straight or slightly curved), 7–11 mm.

Fruits

didymous, mostly highly inflated (strongly flattened at least in 1/2 toward replum), 14–18 × 14–18 mm, (papery, basal sinus slightly notched, apical open, shallow);

valves (retaining seeds after dehiscence), evenly pubescent;

replum lanceolate, 7–10 mm, width 1.5–2.5 mm, as wide as or wider than fruit, apex acute to acuminate;

ovules 8–10 per ovary;

style 5–7 mm.

didymous, highly inflated, 8–22 × 10–25 mm, (papery, basal and apical sinuses deep);

valves (retaining seeds after dehiscence), densely pubescent, trichomes appressed;

replum linear to oblong, as wide as or wider than fruit;

ovules 8 per ovary;

style 7–9 mm.

Seeds

flattened, (2–3 mm).

flattened.

2n

= 48–52, 52, 64, 67–70.

= 16.

Physaria alpestris

Physaria integrifolia

Phenology Flowering May–Jun. Flowering (May-)Jun–Jul(-Aug).
Habitat Alpine scree, rocky ridges, talus slopes, volcanic sands and gravel, serpentine gravel, granitic slopes, mountain shrub, subalpine fir, and whitebark pine communities Calcareous hills and slopes, shale-limestone cliffs, bare steep slopes, red clay banks, shale
Elevation (700-)1300-2400 m ((2300-)4300-7900 ft) 1900-2700 m (6200-8900 ft)
Distribution
from FNA
WA
[WildflowerSearch map]
[BONAP county map]
from FNA
ID; MT; WY
[BONAP county map]
Discussion

Physaria integrifolia has traditionally been recognized as a variety of P. didymocarpa, but it is morphologically and ecologically quite distinctive. Variety monticola (no combination has been made at subspecific rank) is not recognized here; it is considered another example, in the genus, of caudices elongating in response to shifting substrates.

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

Source FNA vol. 7, p. 624. FNA vol. 7, p. 644.
Parent taxa Brassicaceae > tribe Physarieae > Physaria Brassicaceae > tribe Physarieae > Physaria
Sibling taxa
P. acutifolia, P. alpina, P. angustifolia, P. arctica, P. arenosa, P. argyraea, P. arizonica, P. aurea, P. bellii, P. brassicoides, P. calcicola, P. calderi, P. carinata, P. chambersii, P. cinerea, P. condensata, P. congesta, P. cordiformis, P. curvipes, P. densiflora, P. didymocarpa, P. dornii, P. douglasii, P. eburniflora, P. engelmannii, P. eriocarpa, P. fendleri, P. filiformis, P. floribunda, P. fremontii, P. garrettii, P. geyeri, P. globosa, P. gooddingii, P. gordonii, P. gracilis, P. grahamii, P. hemiphysaria, P. hitchcockii, P. humilis, P. integrifolia, P. intermedia, P. kingii, P. klausii, P. lata, P. lepidota, P. lesicii, P. lindheimeri, P. ludoviciana, P. macrocarpa, P. mcvaughiana, P. montana, P. multiceps, P. navajoensis, P. nelsonii, P. newberryi, P. obcordata, P. obdeltata, P. occidentalis, P. oregona, P. ovalifolia, P. pachyphylla, P. pallida, P. parviflora, P. parvula, P. pendula, P. pinetorum, P. prostrata, P. pruinosa, P. pulvinata, P. purpurea, P. pycnantha, P. rectipes, P. recurvata, P. reediana, P. rollinsii, P. saximontana, P. scrotiformis, P. sessilis, P. spatulata, P. subumbellata, P. tenella, P. thamnophila, P. tumulosa, P. valida, P. vicina, P. vitulifera
P. acutifolia, P. alpestris, P. alpina, P. angustifolia, P. arctica, P. arenosa, P. argyraea, P. arizonica, P. aurea, P. bellii, P. brassicoides, P. calcicola, P. calderi, P. carinata, P. chambersii, P. cinerea, P. condensata, P. congesta, P. cordiformis, P. curvipes, P. densiflora, P. didymocarpa, P. dornii, P. douglasii, P. eburniflora, P. engelmannii, P. eriocarpa, P. fendleri, P. filiformis, P. floribunda, P. fremontii, P. garrettii, P. geyeri, P. globosa, P. gooddingii, P. gordonii, P. gracilis, P. grahamii, P. hemiphysaria, P. hitchcockii, P. humilis, P. intermedia, P. kingii, P. klausii, P. lata, P. lepidota, P. lesicii, P. lindheimeri, P. ludoviciana, P. macrocarpa, P. mcvaughiana, P. montana, P. multiceps, P. navajoensis, P. nelsonii, P. newberryi, P. obcordata, P. obdeltata, P. occidentalis, P. oregona, P. ovalifolia, P. pachyphylla, P. pallida, P. parviflora, P. parvula, P. pendula, P. pinetorum, P. prostrata, P. pruinosa, P. pulvinata, P. purpurea, P. pycnantha, P. rectipes, P. recurvata, P. reediana, P. rollinsii, P. saximontana, P. scrotiformis, P. sessilis, P. spatulata, P. subumbellata, P. tenella, P. thamnophila, P. tumulosa, P. valida, P. vicina, P. vitulifera
Synonyms Lesquerella alpestris P. didymocarpa var. integrifolia, P. integrifolia var. monticola
Name authority Suksdorf: W. Amer. Sci. 15: 58. (1906) (Rollins) Lichvar: Madroño 31: 203. (1984)
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