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Bell's or Front Range twinpod, Bell's twinpod, Front Range twinpod

Rollins' twinpod

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

simple from base, decumbent to nearly prostrate, 0.5–1.3 dm.

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

Basal leaves

(strongly rosulate; shortly petiolate);

blade broadly obovate, 1.5–7.5 (width 7.5–26 mm, base gradually tapering to petiole), margins shallowly dentate, (apex obtuse).

(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).

Cauline leaves

blade oblanceolate to broadly obovate, 1–2.5 cm, margins entire.

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

Racemes

dense.

congested, (elongated moderately in fruit).

Flowers

sepals (pale yellow or yellow-green), narrowly lanceolate to narrowly deltate, 4–8 mm;

petals yellow, broadly spatulate to obovate, 9–13 mm, (not clawed).

sepals linear, 5–7 mm;

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

Fruiting pedicels

(divaricate-ascending to widely spreading, slightly sigmoid to curved), 7–12 mm.

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

Fruits

didymous, slightly flattened (contrary to replum) to uncompressed, 4–9 × 2–8 mm, (strongly coriaceous, apical and basal sinuses narrow, deep);

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

replum narrowly oblanceolate to narrowly linear-oblong, as wide as or wider than fruit, apex obtuse;

ovules 4 per ovary;

style more than 3 mm.

(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.

Seeds

compressed.

slightly flattened.

2n

= 8.

= 8.

Physaria bellii

Physaria rollinsii

Phenology Flowering Mar–Jun(-Jul). Flowering May–Jun.
Habitat Dark shale, road cuts, ridge crests, washes Sagebrush, granitic talus, open knolls, limestone chiprock, steep slopes, clay banks, near granite boulders
Elevation 1500-1800 m (4900-5900 ft) 2300-2500(-3900) m (7500-8200(-12800) ft)
Distribution
from FNA
CO
[WildflowerSearch map]
[BONAP county map]
from FNA
CO
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

Physaria bellii is often found in shale and limestone soils of the Fountain/Ingleside, Lykins, Niobrara, and Pierre formations. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.

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

Source FNA vol. 7, p. 628. FNA vol. 7, p. 661.
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. 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. 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
Name authority G. A. Mulligan: Canad. J. Bot. 44: 1662, fig. 1, plate 1, fig. 3. (1966) G. A. Mulligan: Canad. J. Bot. 44: 1663, fig. 2, plate 1, fig. 4. (1966)
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