Physaria gordonii |
Physaria didymocarpa |
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Gordon's bladderpod |
common twinpod, double twinpod, twin bladderpod |
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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. |
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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). |
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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). |
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Racemes | dense. |
congested, (elongated in fruit, greatly exceeding leaves). |
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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. |
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Fruiting pedicels | (divaricate-ascending, sigmoid or, sometimes, nearly straight), 5–15(–25) mm. |
(spreading, straight or slightly curved), 8–12 mm. |
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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. |
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Seeds | flattened. |
flattened. |
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2n | = 12, 32. |
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Physaria gordonii |
Physaria didymocarpa |
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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 |
AZ; KS; NM; OK; TX; VA; Mexico (Chihuahua, Sonora)
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ID; MT; WA; WY; AB; BC
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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.) |
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Key |
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Source | FNA vol. 7, p. 640. | FNA vol. 7, p. 633. | ||||||||
Parent taxa | Brassicaceae > tribe Physarieae > Physaria | Brassicaceae > tribe Physarieae > Physaria | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
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) | ||||||||
Web links |