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Rollins' twinpod

double bladderpod, double twinpod

Habit Perennials; (compact); caudex usually simple, (cespitose); (silvery) pubescent throughout, trichomes 6–8-rayed, rays furcate near base, fused at base, (umbonate, strongly tuberculate throughout). Perennials; (somewhat compact); caudex branched, (relatively large); (silvery) pubescent throughout, trichomes (sessile), several-rayed, rays furcate, (slightly umbonate, tuberculate throughout).
Stems

several from base, decumbent, (unbranched, slender), 0.5–1 dm.

several from base, decumbent to ascending (arising laterally, unbranched, stout), (0.2–)0.5–1.7 dm.

Basal leaves

(strongly rosulate);

blade usually oblanceolate or broader, sometimes triangular, 2–3.5 cm (width 5–10 mm), margins entire or with 1 or 2 broad teeth, (apex acute).

(petiole somewhat winged);

blades orbicular to obovate, 2–6 cm (width 1–2.5 cm, thick), margins usually repand, rarely entire, (adaxial surface scurfy).

Cauline leaves

blade oblanceolate, 1–1.5 cm (width 2–4 mm), margins entire, (apex acute).

blade oblanceolate to broadly spatulate, 1–2 cm (width 3–5 mm), margins entire, (apex obtuse to subacute).

Racemes

congested, (elongated moderately in fruit).

moderately dense (or elongated).

Flowers

sepals linear, 5–7 mm;

petals spatulate, 8–10 mm, (apex often somewhat truncate).

sepals linear-oblong, 6–8 mm;

petals spatulate, 9–12 mm.

Fruiting pedicels

(spreading, straight or somewhat sigmoid), 5–8 mm.

(divergent, straight to somewhat curved or sigmoid), 5–12 mm.

Fruits

(erect), didymous, suborbicular, inflated, 2–5(–8) × 4–8(–10)mm, (coriaceous, base slightly cordate or nearly obtuse, sinus obsolete or absent, apical sinus broad and deep);

valves (retaining seeds after dehiscence), pubescent, trichomes appressed, (silvery on ovaries and immature fruit);

replum obovate to oblong, as wide as or wider than fruit, rarely somewhat constricted basally, apex obtuse;

ovules 4 per ovary;

style 5–7 mm.

(erect), didymous, cordate, moderately inflated, (6–)10–20 × 10–23 mm, (papery, base obtuse or with obscure sinus, apical sinus deep, broad);

valves (retaining seeds after dehiscence), densely and loosely pubescent, trichomes spreading;

replum linear-oblong, constricted, as wide as or wider than fruit;

ovules 4 per ovary;

style 4–5(–9) mm.

Seeds

slightly flattened.

plump, (broad).

2n

= 8.

= 8, 16.

Physaria rollinsii

Physaria brassicoides

Phenology Flowering May–Jun. Flowering May–Jun.
Habitat Sagebrush, granitic talus, open knolls, limestone chiprock, steep slopes, clay banks, near granite boulders Bare hillsides, dry gravel and clay soil, badlands, clay knolls, banks
Elevation 2300-2500(-3900) m (7500-8200(-12800) ft) 900-1400 m (3000-4600 ft)
Distribution
from FNA
CO
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; MT; ND; NE; SD; WY
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 7, p. 661. FNA vol. 7, p. 628.
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. 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. 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. 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
Name authority G. A. Mulligan: Canad. J. Bot. 44: 1663, fig. 2, plate 1, fig. 4. (1966) Rydberg: Bull. Torrey Bot. Club 29: 237. (1902)
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