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Gordon's bladderpod

common twinpod, double twinpod, twin bladderpod

Habit Annuals, biennials, or perennials; (short-lived); with a fine taproot; usually densely pubescent, trichomes (sessile or short-stalked), 4–7-rayed, rays distinct and furcate or bifurcate, (nearly smooth to finely tuberculate). 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).
Stems

several from base, erect to decumbent or prostrate, (unbranched or branched, sometimes densely leaved), 1–3.5(–4.5) dm.

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

Basal leaves

blade obovate to broadly oblong, 1.5–5(–8) cm, margins lyrate-pinnatifid, dentate, or entire.

(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).

Cauline leaves

(proximal sometimes petiolate, distal sessile);

blade linear to oblanceolate, often falcate, 1–4(–7) cm, (proximal with base sometimes cuneate), margins entire, repand, or shallowly dentate.

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

Racemes

dense.

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

Flowers

sepals elliptic or oblong, 3–6.5 mm, (lateral pair subsaccate, median pair thickened apically, cucullate);

petals (widely spreading at anthesis, yellow to orange, claw sometimes whitish), cuneate, obdeltate, or obovate, (tapering to claw), 5–8(–10) mm, (claw often widened at base).

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

petals spatulate, 10–12 mm.

Fruiting pedicels

(divaricate-ascending, sigmoid or, sometimes, nearly straight), 5–15(–25) mm.

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

Fruits

(shortly stipitate), subglobose, not or slightly compressed, (3–)4–8 mm;

valves (not retaining seeds after dehiscence), glabrous throughout;

replum as wide as or wider than fruit;

ovules (8–)12–20(–26) per ovary;

style (1.5–)2–4(–5) 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.

Seeds

flattened.

flattened.

2n

= 12, 32.

Physaria gordonii

Physaria didymocarpa

Phenology Flowering Feb–Jul.
Habitat Sandy or light soils, rocky plains, caprock ledges, gravelly brushland, sandy desert washes, stream bottoms, pastures, roadsides, abandoned fields
Elevation 150-1700 m (500-5600 ft)
Distribution
from FNA
AZ; KS; NM; OK; TX; VA; Mexico (Chihuahua, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
ID; MT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Physaria gordonii was reported from Virginia in 1987 by Robert Wright from a Hampton Shale roadcut along the Blue Ridge Parkway, where it was probably a short-lived waif.

Subspecies densifolia, of Lincoln County, New Mexico, of which there is now more material than Rollins had available in 1993, appears to represent a suite of environmentally determined, variable, and intergrading characteristics that does not merit taxonomic recognition.

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

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. 640. FNA vol. 7, p. 633.
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. 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. 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
Subordinate taxa
P. didymocarpa subsp. didymocarpa, P. didymocarpa subsp. lanata, P. didymocarpa subsp. lyrata
Synonyms Vesicaria gordonii, Alyssum gordonii, Lesquerella gordonii, Lesquerella gordonii var. densifolia, P. gordonii subsp. densifolia, P. gordonii var. densifolia Vesicaria didymocarpa, Coulterina didymocarpa
Name authority (A. Gray) O’Kane & Al-Shehbaz: Novon 12: 323. (2002) (Hooker) A. Gray: Gen. Amer. Bor. 1: 162. (1848)
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