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common twinpod, double twinpod, twin bladderpod

alpine bladderpod, reed's twinpod, Rollins' bladderpod

Habit Perennials; caudex branched, (cespitose); densely pubescent, trichomes (often stalked, appressed to wavy and spreading), several-rayed, rays furcate or simple, (slightly to strongly umbonate, nearly smooth to strongly tuberculate). Perennials; caudex simple or branched, (covered with persistent leaf bases, loosely cespitose); densely pubescent, trichomes (appressed to ascending, plant appearing shaggy, always appressed on fruits), 4- or 5-rayed, rays furcate or bifurcate, (tuberculate throughout).
Stems

several from base, decumbent, (unbranched, leafy for the genus), ca. 1 dm.

few to several from base, ± erect, (arising laterally, also from within basal leaves), 0.2–0.4 dm.

Basal leaves

(forming a strong rosette; long-petiolate);

blade obovate, 1.5–4(–8) cm, (base ± abruptly narrowing to petiole), margins usually repand or dentate, rarely entire, (apex usually angular, surfaces silvery).

(erect);

blade linear-oblanceolate, 1.2–2.8 cm, (base gradually narrowed to petiole), margins entire.

Cauline leaves

blade oblanceolate, 1–2 cm (width 4–8 mm), margins entire or with occasional tooth, (apex acute).

blade linear, similar to basal.

Racemes

congested, (elongated in fruit, greatly exceeding leaves).

dense, (often subumbellate, not or barely exceeding basal leaves).

Flowers

sepals lanceolate to oblong, 6–8 mm, (often keeled);

petals spatulate, 10–12 mm.

sepals (pale green-yellow), oblong to elliptic, 4–5 mm, (median pair usually thickened apically, cucullate);

petals lingulate, 6–9 mm.

Fruiting pedicels

(spreading, straight or slightly curved), 8–12 mm.

(ascending, curved), 3–5.5 mm.

Fruits

(erect), didymous, inflated, 10–20 × 10–20 mm, (papery or firm, basal sinus shallow to deep, sometimes barely notched, apical sinus deep, narrow, usually closed);

valves (retaining seeds after dehiscence), loosely pubescent, trichomes spreading (appearing fuzzy);

replum obovate to broadly oblong, not constricted, 3–4 mm, as wide as or wider than fruit, apex obtuse;

ovules (4–)8 per ovary;

style 7–9 mm.

lanceolate in outline, compressed (latiseptate) on margins and at apex, 4–5 mm;

valves pubescent, trichomes closely appressed;

ovules 8–12 per ovary;

style 3.5–4.5 mm (equaling or exceeding length of fruit, curved proximal to stigma).

Seeds

flattened.

plump, (oblong).

Physaria didymocarpa

Physaria reediana

Phenology Flowering May–Jul.
Habitat Open areas of grasslands on calcareous soils
Elevation 1200-1900 m (3900-6200 ft)
Distribution
from FNA
ID; MT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; NE; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Subspecies 3 (3 in the flora).

The characters used to differentiate Physaria didymocarpa from P. saximontana (especially subsp. dentata) appear to be weak at best: whether there are 4 or 8 ovules per ovary and whether the silicle lacks a basal sinus or one is present. There appears to be intergradation in each of those characters. A traditional circumscription of these species is followed here. Further work is needed at both the species and subspecies level in these taxa.

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

Key
1. Trichomes spreading throughout; basal leaf blade margins dentate.
subsp. lanata
1. Trichomes appressed (except fruits in subsp. didymocarpa); basal leaf blade margins repand to dentate, ± lyrate or, rarely, entire
→ 2
2. Fruits moderately inflated, trichomes spreading.
subsp. didymocarpa
2. Fruits highly inflated (papery), trichomes appressed.
subsp. lyrata
Source FNA vol. 7, p. 633. FNA vol. 7, p. 660.
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. 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. rollinsii, P. saximontana, P. scrotiformis, P. sessilis, P. spatulata, P. subumbellata, P. tenella, P. thamnophila, P. tumulosa, P. valida, P. vicina, P. vitulifera
Subordinate taxa
P. didymocarpa subsp. didymocarpa, P. didymocarpa subsp. lanata, P. didymocarpa subsp. lyrata
Synonyms Vesicaria didymocarpa, Coulterina didymocarpa Vesicaria alpina, Alyssum alpinum, Lesquerella alpina, Lesquerella alpina var. laevis, Lesquerella condensata var. laevis
Name authority (Hooker) A. Gray: Gen. Amer. Bor. 1: 162. (1848) O’Kane & Al-Shehbaz: Novon 12: 327. (2002)
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