Physaria didymocarpa
Physaria chambersii
common twinpod, double twinpod, twin bladderpod
Chambers' bladder-pod, Chambers' physaria, Chambers' twinpod, double bladderpod
several from base, decumbent, (unbranched, leafy for the genus), ca. 1 dm.
several from base, erect or decumbent (arising laterally, unbranched), 0.5–1.5 mm.
(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).
(petiole slender);
blade obovate to orbicular, 3–6 cm (width 10–20 mm), margins entire or dentate.
blade oblanceolate, 1–2 cm (width 4–8 mm), margins entire or with occasional tooth, (apex acute).
blade spatulate, 1–2 cm (width 3–6 mm), margins entire, (apex often acute).
congested, (elongated in fruit, greatly exceeding leaves).
congested.
sepals lanceolate to oblong, 6–8 mm, (often keeled);
petals spatulate, 10–12 mm.
sepals narrowly lanceolate, 5–8(–9) mm;
petals narrowly oblanceolate, 9–12 mm, (claw undifferentiated from blade).
(spreading, straight or slightly curved), 8–12 mm.
(divaricate, slightly sigmoid), 8–15 mm.
(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.
(often purplish in age), didymous, subreniform, strongly inflated, 9–18 × 11–21(–30) mm, (papery, base obtuse to slightly cordate, apical sinus V-shaped or convex, open crests rounded);
valves (2-keeled on side away from replum, each 3-sided, keels rounded, sides flat or slightly convex, retaining seeds after dehiscence), evenly and densely pubescent;
replum oblong, as wide as or wider than fruits, apex obtuse;
ovules 4–12 per ovary;
style (4–)6–8 mm (exceeding sinus).
flattened.
flattened.
= 8, 10, 16, 24.
Physaria didymocarpa
Physaria chambersii
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.)
Physaria chambersii has been divided into three varieties based on whether the fruit is stipitate (var. canaani) or not, and whether the caudex elongates (var. sobolifera) or not (var. chambersii). In this species and in some others, e.g., P. newberryi, the latter character often depends on substrate and microclimate. Shifting substrates, such as moving sand and talus, often cause caudices to elongate. The species can be confused with 57. P. newberryi.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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 |
BC
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CA
OR
