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Oregon twin-pod

double bladderpod, pointleaf twinpod, Rydberg's twinpod, sharpleaf twinpod

Habit Perennials; caudex simple, (cespitose); (silvery) pubescent throughout, trichomes (stalked), few-rayed, rays furcate or imperfectly so, (tuberculate throughout). Perennials; caudex branched, (sometimes forming a thick crown, cespitose); (silvery) pubescent throughout, trichomes several-rayed, rays furcate, (moderately tuberculate, rays weakly so).
Stems

several from base, erect or somewhat decumbent, (unbranched), 1–3.5 dm.

several from base, usually somewhat decumbent, (unbranched), (0.4–)0.5–2 dm.

Basal leaves

(petiole slender, usually incised or with broad teeth along petiole);

blade obovate, 4–6 cm, margins entire.

(petiole slender, often narrowly winged);

blade obovate to orbicular or rhombic-orbicular, 2–9 cm, (base abruptly narrowed to petiole), margins usually entire, rarely with few scattered teeth, (apex rounded or obtuse, sometimes with apical mucro).

Cauline leaves

blade oblanceolate or broader, 1.5–2.5 cm, margins entire or sparsely dentate, (apex acute).

blade spatulate to oblanceolate, 1–3 cm, margins entire, (apex usually obtuse).

Racemes

somewhat loose, (5–15 cm).

loose, (elongated in fruit).

Flowers

sepals oblong, 5–7 mm;

petals (lemon yellow), spatulate, 9–12 mm.

sepals linear-oblong, 4–7.5 mm;

petals spatulate, 6–11 mm.

Fruiting pedicels

(spreading or ascending, curved, fruits not pendent), 10–20 mm.

(divaricate, slightly sigmoid or nearly straight), 6–12 mm.

Fruits

didymous, obreniform, moderately inflated, angustispetate, (8–)10–12(–15) × 10–14(–16) mm, (papery, not keeled, basal sinus absent, apical sinus broad and open);

valves (retaining seeds after dehiscence, rounded or irregular), loosely pubescent, trichomes spreading;

replum broadly lanceolate, as wide as or wider than fruit, apex acute;

ovules 8 per ovary;

style 1–2 mm.

(erect), didymous, suborbicular, inflated, (4–)6–15 × (4–)8–20 mm, (papery, basal and apical sinuses similar, basal rarely shallower, apical deep, narrow and closed or nearly so);

valves retaining seeds after dehiscence, pubescent, trichomes appressed;

replum oblong, constricted, 2–3.5 mm, narrower than fruit, apex obtuse;

ovules (2 or) 4 per ovary;

style 4–6(–9) mm.

Seeds

flattened.

(dark brown), flattened, (2–3 mm).

2n

= 8.

= 10, 16, 24.

Physaria oregona

Physaria acutifolia

Phenology Flowering Apr–Jun. Flowering May–Jun(-Jul).
Habitat Gravelly banks, stream shores, rocky slopes, dry hillsides, serpentine soils Hillsides, roadcuts, sagebrush, pinyon-juniper, Gambel oak, ponderosa pine communities
Elevation 900-1900 m (3000-6200 ft) 1500-3500 m (4900-11500 ft)
Distribution
from FNA
ID; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; ID; MT; NM; NV; SD; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Physaria acutifolia tends to be somewhat dwarfed, with a branched caudex and especially long styles (var. stylosa), where it grows at high elevations, especially at the western end of the Uinta Mountains in Utah. Intermediates form an uninterrupted cline and no infraspecific taxa are here recognized. In R. C. Rollins (1939), the discussion of P. acutifolia actually pertains to P. rollinsii. The discussion of P. australis pertains to what is now known as P. acutifolia. The plants are usually found in open soil patches, rarely into the subalpine or alpine tundra.

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

Source FNA vol. 7, p. 655. FNA vol. 7, p. 624.
Parent taxa Brassicaceae > tribe Physarieae > Physaria Brassicaceae > tribe Physarieae > Physaria
Sibling taxa
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. 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. 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. 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. 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
Synonyms Coulterina oregona, Lesquerella oregona P. acutifolia var. stylosa, P. australis, P. didymocarpa var. australis, P. stylosa
Name authority S. Watson: Proc. Amer. Acad. Arts 17: 363. (1882) Rydberg: Bull. Torrey Bot. Club 28: 279. (1901)
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