Physaria

Annuals, biennials, or perennials; (caudex often present, enlarged, usually branched); not scapose; usually pubescent, trichomes usually sessile, sometimes subsessile or shortly stalked, usually stellate, sometimes stellate-scalelike, rarely simple. Stems erect, spreading, decumbent, or prostrate, unbranched or branched distally. Leaves basal and cauline; petiolate or sessile; basal usually rosulate, petiolate, blade margins usually entire, sometimes repand to pinnatifid; cauline petiolate or sessile, blade margins usually entire, sometimes repand to dentate. Racemes (few- to several-flowered, proximalmost flowers rarely bracteate), elongated or not in fruit. Fruiting pedicels erect, horizontal, divaricate, spreading, ascending, or sigmoid, usually slender, sometimes stout. Flowers: sepals erect or spreading, linear, lanceolate, elliptic, oblong, ovate, or deltate, lateral pair usually saccate basally, sometimes subsaccate or not saccate; petals usually yellow, sometimes orange (occasionally drying purplish or maroon), rarely white or purple, spatulate, obovate, ovate, oblanceolate, or obdeltate, (longer than sepals), claw differentiated or not from blade, (apex usually rounded, rarely slightly emarginate); stamens tetradynamous; filaments usually not dilated basally; anthers ovate to narrowly oblong, (apex usually obtuse); nectar glands confluent, subtending bases of stamens, median glands present or absent. Fruits silicles, sessile, subsessile or, rarely, shortly stipitate, globose, subglobose, orbicular, suborbicular, ellipsoid, elliptic, lanceolate, obcordate, obdeltate, oblong, obpyriform, ovate, ovoid, or obovoid, not torulose, inflated or not, terete, latiseptate, or angustiseptate; valves each often with obscure midvein, (usually not retaining seeds after dehiscence), usually pubescent, sometimes glabrous, or, rarely, pubescent inside; replum rounded to narrowly oblong; septum usually complete, sometimes perforate, or, rarely, reduced to a rim (often with apical midvein extending to center); ovules (2–)4–32(–40[–80]) per ovary; style distinct; stigma entire. Seeds biseriate, often flattened, sometimes plump, rarely lenticular, usually not winged, rarely narrowly winged or margined, often suborbicular; seed coat (smooth), mucilaginous or not when wetted; cotyledons accumbent. x = 4, 5, 6, 7, 8, 9, 10, 12, 15.

Distribution

North America, n Mexico, s South America (Argentina, s Bolivia), Asia (ne Russia).

Discussion

Species 106 (88 in the flora).

Seeds of Physaria contain hydroxy fatty acids, and some species, notably P. fendleri, are being intensively studied as a source of specialized, high-quality lubricants. The genus is notable for its relatively large number of local, often endangered, and edaphically-determined (usually calciphilic) endemics. Most of the genus Lesquerella (except for the auriculate-leaved species placed in Paysonia O’Kane & Al-Shehbaz) was recently united with Physaria, which is now much larger but monophyletic and morphologically coherent (I. A. Al-Shehbaz and S. L. O’Kane 2002). Where details of the trichomes are sparse, this is due to an absence of electron microscopy for these taxa (although the number of primary rays and some details are often visible at 10–30× with glancing light). The number of rays of the ubiquitous unicellular, stellate trichomes refers to the primary divisions immediately proximal to the center of the trichome. These primary rays are then typically furcate or bifurcate, often imperfectly so (2 + 1 branches, rather than 2 + 2). Trichome rays are usually appressed or parallel to surfaces on a short stalk; when the rays flare from surfaces, this is noted in the descriptions. Umbonate trichomes have a distinctive raised mound at the center; unless otherwise stated, trichomes are not umbonate. Tubercles are bumps or granules scattered along the rays and often over the center of the trichome. Flowering is likely to occur earlier than indicated in the descriptions, because specimens are typically (and optimally) collected when the fruits are nearly or fully mature, rather than when plants are only in flower. Raceme descriptions refer to mature infructescences unless otherwise noted. In Physaria, didymous is used as a term for fruit shape. A didymous fruit is inflated and appears as two balloons pressed together. The overall fruit shape is otherwise difficult to define and authors have traditionally referred to it this way. Replum shape and placement of the valve orifice are reported for only those taxa that were traditionally placed in Physaria, in the strict sense, where replum shape is sometimes helpful in separating species. The valves of didymous-fruited Physaria typically do not release their seeds; the valves and seeds disperse as a unit; species previously placed in Lesquerella freely release their seeds. The number of ovules reported, easily ascertained by counting funiculi, is most often greater than the number of seeds that occupy the fruit, either because of abortion or lack of fertilization. Species with mucilaginous seeds typically occupy steep and/or unstable habitats; when wetted, mucilaginous seeds can be “glued” onto optimal, local habitats.

Selected References

Al-Shehbaz, I. A. and S. L. O’Kane. 2002. Lesquerella is united with Physaria. Novon 12: 319–329.

Mulligan, G. A. 1968. Physaria didymocarpa, P. brassicoides, and P. floribunda (Cruciferae) and their close relatives. Canad. J. Bot. 46: 735–740.

Payson, E. B. 1921. A monograph of the genus Lesquerella. Ann. Missouri Bot. Gard. 8: 103–236.

Rollins, R. C. 1939. The cruciferous genus Physaria. Rhodora 41: 392–415.

Rollins, R. C. 1939b. Studies in the genus Lesquerella. Amer. J. Bot. 26: 419–421.

Rollins, R. C. and E. A Shaw. 1973. The Genus Lesquerella (Cruciferae) in North America. Cambridge, Mass.

Rollins, R. C. and U. C. Banerjee. 1975. Atlas of the trichomes of Lesquerella (Cruciferae). Publ. Bussey Inst. Harvard Univ. 1975: 1–48.

Rollins, R. C. and U. C. Banerjee. 1979b. Trichome patterns in Physaria. Publ. Bussey Inst. Harvard Univ. 1979: 65–77.

Rollins, R. C. 1981b. Studies in the genus Physaria (Cruciferae). Brittonia 33: 332–341.

Lower Taxa

Physaria acutifolia, Physaria alpestris, Physaria alpina, Physaria angustifolia, Physaria arctica, Physaria arenosa, Physaria argyraea, Physaria arizonica, Physaria aurea, Physaria bellii, Physaria brassicoides, Physaria calcicola, Physaria calderi, Physaria carinata, Physaria chambersii, Physaria cinerea, Physaria condensata, Physaria congesta, Physaria cordiformis, Physaria curvipes, Physaria densiflora, Physaria didymocarpa, Physaria dornii, Physaria douglasii, Physaria eburniflora, Physaria engelmannii, Physaria eriocarpa, Physaria fendleri, Physaria filiformis, Physaria floribunda, Physaria fremontii, Physaria garrettii, Physaria geyeri, Physaria globosa, Physaria gooddingii, Physaria gordonii, Physaria gracilis, Physaria grahamii, Physaria hemiphysaria, Physaria hitchcockii, Physaria humilis, Physaria integrifolia, Physaria intermedia, Physaria kingii, Physaria klausii, Physaria lata, Physaria lepidota, Physaria lesicae, Physaria lindheimeri, Physaria ludoviciana, Physaria macrocarpa, Physaria mcvaughiana, Physaria montana, Physaria multiceps, Physaria navajoensis, Physaria nelsonii, Physaria newberryi, Physaria obcordata, Physaria obdeltata, Physaria occidentalis, Physaria oregona, Physaria ovalifolia, Physaria pachyphylla, Physaria pallida, Physaria parviflora, Physaria parvula, Physaria pendula, Physaria pinetorum, Physaria prostrata, Physaria pruinosa, Physaria pulvinata, Physaria purpurea, Physaria pycnantha, Physaria rectipes, Physaria recurvata, Physaria reediana, Physaria rollinsii, Physaria saximontana, Physaria scrotiformis, Physaria sessilis, Physaria spatulata, Physaria subumbellata, Physaria tenella, Physaria thamnophila, Physaria tumulosa, Physaria valida, Physaria vicina, Physaria vitulifera

Key

1	Fruits papery (coriaceous in P. bellii, P. rollinsii), inflated (often double, didymous); valves retaining seeds after dehiscence, basal sinus usually present, sometimes absent; replum narrower than fruit (traditional Physaria in the strict sense)	> 2
1	Fruits firm, not or slightly inflated (not didymous); valves not retaining seeds after dehiscence, basal sinus absent; replum usually as wide as or wider than fruit (traditional Lesquerella in the strict sense)	> 23
2	Fruits somewhat inflated, not didymous, angustiseptate.	Physaria geyeri
2	Fruits inflated, strongly didymous at least apically, not angustiseptate (except P. alpestris)	> 3
3	Petals white.	Physaria eburniflora
3	Petals yellow (sometimes drying purplish) or yellow and purple-tinged	> 4
4	Trichomes stellate-scalelike [rays fused (webbed)]	> 5
4	Trichomes stellate	> 6
5	Fruits strongly didymous, highly inflated, basal sinus shallow; sc Utah.	Physaria lepidota
5	Fruits slightly didymous, slightly inflated, basal sinus absent; Piceance Basin, Colorado.	Physaria obcordata
6	Fruiting pedicels recurved; fruits nearly pendent; basal leaf blades: margins dentate or pinnatifid (rarely subentire).	Physaria floribunda
6	Fruiting pedicels not recurved; fruits erect, spreading, ascending, not pendent; basal leaf blades: margins entire, few-toothed, dentate, repand, or lyrate-lobed	> 7
7	Fruit valves keeled (2-keeled on side away from replum)	> 8
7	Fruit valves rounded or irregular, not keeled	> 9
8	Valves with sides flat or slightly convex, keels rounded, apical sinus V-shaped or convex; styles (4-)6-8 mm.	Physaria chambersii
8	Valves with sides concave, keels sharp-angled, apical sinus concave; styles 2-9 mm.	Physaria newberryi
9	Styles less than 3 mm; fruits: basal sinus absent.	Physaria oregona
9	Styles greater than 3 mm; fruits: basal sinus present or absent	> 10
10	Fruits strongly angustiseptate (at least toward replum); replums: apex acute to acuminate.	Physaria alpestris
10	Fruits not angustiseptate; replums: apex usually obtuse	> 11
11	Petals 10-12(-15) mm; fruits irregularly angled and roughened, not strongly inflated; plants of alpine Colorado.	Physaria alpina
11	Petals 6-14 mm; fruits irregular in shape, or suborbicular, subglobose, cordate, or angular, usually inflated; plants usually not alpine (if so, fruits rounded, strongly inflated)	> 12
12	Fruits: basal sinus obscure or absent, apical sinus deeper	> 13
12	Fruits: basal and apical sinuses well-developed, usually ± equal	> 16
13	Fruit valves: trichomes with spreading rays (ovaries and immature fruits fuzzy)	> 14
13	Fruit valves: trichomes with appressed or spreading rays (ovaries and immature fruits silvery, not fuzzy)	> 15
14	Blades of younger basal leaves tapered to petioles; apical sinus of fruits usually broad (often giving fruits a flared appearance).	Physaria brassicoides
14	Blades of all basal leaves abruptly narrowed to petioles; apical sinus of fruits narrow.	Physaria saximontana
15	Plants compact; stems decumbent; fruiting pedicels straight.	Physaria rollinsii
15	Plants not usually compact; stems decumbent to ascending; fruiting pedicels sigmoid.	Physaria vitulifera
16	Ovules mostly 4 per ovary	> 17
16	Ovules (4-)8(-12) per ovary	> 20
17	Fruit valves: trichomes with ascending rays (appearing fuzzy)	> 18
17	Fruit valves: trichomes with appressed rays (not appearing fuzzy)	> 19
18	Replum obovate to broadly oblong; Idaho, Montana, Washington, Wyoming.	Physaria didymocarpa
18	Replum oblong to oblanceolate; c, ec Utah.	Physaria grahamii
19	Basal leaf blades: base abruptly narrowed to petioles, margins usually entire, rarely with scattered teeth, apex rounded or obtuse (sometimes with apical mucro).	Physaria acutifolia
19	Basal leaf blades: base gradually tapering to petioles, margins shallowly dentate, apex obtuse.	Physaria bellii
20	Plants compact (from condensed rosette); racemes barely exceeding leaves	> 21
20	Plants loose (cespitose); racemes greatly exceeding leaves	> 22
21	Basal leaves mostly horizontal, blades 0.5-1.5 cm × 40-80 mm; replums 3-4 mm.	Physaria condensata
21	Basal leaves ascending or erect, blades (1.5-)5-7 cm × 12-20 mm; replums 1-1.8 mm.	Physaria dornii
22	Leaf blade margins usually dentate or repand, bases ± abruptly narrowing to petioles.	Physaria didymocarpa
22	Leaf blade margins entire, bases mostly abruptly tapering to petioles.	Physaria integrifolia
23	Fruit valves glabrous outside	> 24
23	Fruit valves pubescent outside	> 50
24	Annuals or biennials (usually with a fine taproot)	> 25
24	Perennials or, rarely, biennials (with caudex, except P. gordonii)	> 33
25	Petals white.	Physaria pallida
25	Petals yellow (sometimes drying purplish), yellow and purple-tinged, or orange	> 26
26	Basal and cauline leaves similar in shape	> 27
26	Basal and cauline leaves different in shape	> 29
27	Fruits sessile or shortly stipitate.	Physaria angustifolia
27	Fruits stipitate (gynophores 0.5-2 mm)	> 28
28	Gynophores 0.5-1 mm; fruiting pedicels sigmoid.	Physaria gordonii
28	Gynophores 1-2 mm; fruiting pedicels straight or slightly curved.	Physaria gracilis
29	Fruiting pedicels recurved.	Physaria recurvata
29	Fruiting pedicels usually erect, straight, ascending, or sigmoid	> 30
30	Ovules 4 per ovary.	Physaria filiformis
30	Ovules 8-20 per ovary	> 31
31	Fruit valves papillose outside, densely pubescent inside.	Physaria sessilis
31	Fruit valves smooth outside, glabrous inside	> 32
32	Pedicels straight or slightly curved; trichomes with a U-shaped notch on one side.	Physaria densiflora
32	Pedicels sigmoid, horizontal, or recurved; trichomes without a U-shaped notch.	Physaria lindheimeri
33	Arctic and subarctic (Alaska, Alberta, British Columbia, Greenland, Manitoba, Newfoundland and Labrador, Northwest Territories, Nunavut, Quebec, Yukon)	> 34
33	Dry temperate or subtropical areas (not Alaska, Alberta, British Columbia, Greenland, Manitoba, Newfoundland and Labrador, Northwest Territories, Nunavut, Quebec, Yukon)	> 35
34	Petals spatulate, blade gradually narrowed to claw, 5-6(-7) mm; fruits mostly uncompressed.	Physaria arctica
34	Petals obovate, blade abruptly narrowed to claw, (6-)7-10 mm; fruits usually compressed (angustiseptate).	Physaria calderi
35	Plants pulvinate-cespitose, or forming mounds, mats, or tufts	> 36
35	Plants not cespitose, not forming mounds, mats, or tufts	> 38
36	Petioles and leaf blades differentiated (or slightly so); plants forming soft mats or tufts.	Physaria hitchcockii
36	Petioles and leaf blades undifferentiated; plants forming hard mats	> 37
37	Seeds strongly mucilaginous when wetted; petals deep yellow and slightly orange in center, blade and claw joined at right angle; sepals elliptic; San Juan and McKinley counties, New Mexico, Apache County, Arizona.	Physaria navajoensis
37	Seeds not mucilaginous when wetted; petals yellow, blade and claw joined in an arch; sepals elliptic or oblong; Kane County, Utah.	Physaria tumulosa
38	Trichome rays fused (webbed) 1/2 or most of their length	> 39
38	Trichome rays not fused or only basally	> 40
39	Basal and cauline leaf blade shapes similar.	Physaria fendleri
39	Basal and cauline leaf blade shapes different.	Physaria mcvaughiana
40	Petals white, sometimes purple-veined (fading purplish)	> 41
40	Petals yellow or yellow and orange (sometimes fading purplish)	> 42
41	Basal leaf blades suborbicular to elliptic, or ovate or deltate, 0.5-2(-6.5) cm; petals 8-15 mm.	Physaria ovalifolia
41	Basal leaf blades elliptic or obovate to oblong, 4-15 cm; petals 4.5-10(-12) mm.	Physaria purpurea
42	Fruits obcordate or obdeltate, compressed (angustiseptate).	Physaria hemiphysaria
42	Fruits globose, subglobose, ellipsoid, ovoid, or obovoid, slightly compressed or terete	> 43
43	Trichomes asymmetrical with a deep notch (on one side).	Physaria engelmannii
43	Trichomes symmetrical without a notch	> 44
44	Fruiting pedicels recurved; fruits ± pendent	> 45
44	Fruiting pedicels not recurved (sigmoid, straight, or curved); fruits not pendent	> 46
45	Biennials or short-lived perennials, without a woody caudex.	Physaria aurea
45	Perennials, with a woody caudex.	Physaria thamnophila
46	Ovules 16-32 per ovary; cauline leaves densely overlapping, erect and often appressed.	Physaria argyraea
46	Ovules 4-24(-26) per ovary; cauline leaves not overlapping, not erect and not appressed	> 47
47	Basal leaf blades and petioles differentiated, blades suborbicular, elliptic, ovate, deltate, or obovate to rhombic	> 48
47	Basal leaf blades and petioles not differentiated (tapering), blades obovate, oblong, rhombic to elliptic, or spatulate to oblanceolate	> 49
48	Cauline leaf blades elliptic or obovate; racemes not elongated (subumbellate to densely corymbiform).	Physaria ovalifolia
48	Cauline leaf blades obovate to rhombic; racemes elongated.	Physaria pruinosa
49	Stems prostrate; cauline leaves densely overlapping.	Physaria gordonii
49	Stems ascending to erect; cauline leaves (relatively few), not or loosely over- lapping.	Physaria pinetorum
50	Petals white or cream-white	> 51
50	Petals yellow or orange (sometimes drying purplish)	> 52
51	Basal leaf blades not abruptly narrowed to petioles; Kaibab Plateau, n Arizona.	Physaria kingii
51	Basal leaf blades abruptly narrowed to petioles; Montrose and Ouray counties, Colorado.	Physaria vicina
52	Basal and cauline leaf blades similar in shape (usually narrow), blades less than 5 mm wide, not differentiated from (tapering to) petioles	> 53
52	Basal and cauline leaves dissimilar in shape, blades sometimes greater than 5(-6.5) mm wide, differentiated from petioles	> 66
53	Plants forming dense, hard mats, caudices highly branched (sw Colorado).	Physaria pulvinata
53	Plants not forming dense, hard mats, caudices usually simple or few-branched	> 54
54	Fruiting pedicels usually recurved, sometimes divaricate-spreading or nearly horizontal	> 55
54	Fruiting pedicels ascending, sigmoid, erect, spreading, recurved	> 56
55	Annuals or perennials (short-lived); basal leaf blades flat, margins entire or dentate; racemes secund.	Physaria arenosa
55	Perennials; basal leaf blades involute, margins usually entire (rarely shallowly dentate); racemes not secund.	Physaria ludoviciana
56	Fruit valves: trichomes with erect or spreading rays (± fuzzy in appearance)	> 57
56	Fruit valves: trichomes with appressed rays	> 60
57	Basal leaf blades obovate to orbicular, margins folded; petioles differentiated from blades; caudices thickened (± 1 cm diam.); Sheep Mountain, Pioneer Range, Montana.	Physaria eriocarpa
57	Basal leaf blades linear to oblanceolate, margins not folded; petioles not differentiated from blades; caudices not thickened; Arizona, Idaho, Montana, Wyoming	> 58
58	Styles 2.5-4 mm (as long as or longer than mature fruits); fruits 2.5-3(-4) mm.	Physaria nelsonii
58	Styles (0.5-)1-3(-4) mm (shorter than mature fruits); fruits 3.5-7 mm	> 59
59	Stems simple or few to several from branched caudices (each with a sub-basal tuft of leaves); n Arizona, s Utah.	Physaria arizonica
59	Stems few to several from few-branched or unbranched caudices (each laterally from a basal tuft of rosette leaves); Idaho, se Montana.	Physaria pycnantha
60	Basal blades usually involute, sometimes flattened, linear to linear-oblanceolate, or narrowly spatulate	> 61
60	Basal blades flattened, not involute, linear, linear-oblanceolate, spatulate to nearly rhombic, oblanceolate, or elliptic	> 62
61	Sepals 4.5-7.5(-9) mm; styles (2-)3-4.5(-5.5) mm; pedicels straight or curved-ascending; n Arizona, n New Mexico, c, s Utah.	Physaria intermedia
61	Sepals 3.5-7 mm; styles 2-4 mm; pedicels sigmoid to curved- ascending; nw Colorado, ne Utah, sw Wyoming.	Physaria parvula
62	Racemes not or barely exceeding basal leaves; fruits compressed (latiseptate) on margins and at apices	> 63
62	Racemes exceeding basal leaves; fruits not compressed (or barely so on distal margins and apices) or strongly compressed (latiseptate) throughout	> 64
63	Plants strongly condensed; stems lateral from a tight hemispherical tuft of leaves; Piceance Basin of Colorado.	Physaria congesta
63	Plants not condensed (loosely cespitose); stems lateral and also from within a basal tuft of leaves; nw Colorado, sw Nebraska, se Wyoming.	Physaria reediana
64	Fruits compressed throughout (strongly latiseptate, more so at apices); Montana, Wyoming (Big Horn Mountains).	Physaria curvipes
64	Fruits not compressed at apices or distal margins; Arizona, s Colorado, n New Mexico, s Utah	> 65
65	Basal leaf blades linear; cauline leaves not secund; plants compact.	Physaria calcicola
65	Basal leaf blades narrowly oblanceolate to broadly elliptic; cauline leaves usually secund; plants not compact (loose, spreading).	Physaria rectipes
66	Silicles strongly latiseptate (the valves strongly compressed parallel to the septum)	> 67
66	Silicles not compressed or slightly to strongly angustiseptate (the valves compressed perpendicular to the septum) or very slightly latiseptate	> 68
67	Annuals or biennials; stems branched or unbranched; e Arizona, w New Mexico.	Physaria gooddingii
67	Perennials; stems usually unbranched; California, Idaho, Nevada, Oregon, n Utah, Washington.	Physaria occidentalis
68	Fruits usually strongly compressed (angustiseptate, if slightly so, fruits obdeltate or obcordate)	> 69
68	Fruits usually not compressed (or slightly so at apices, if slightly compressed, fruits not obcordate or obdeltate)	> 72
69	Fruits elliptic to orbicular; Idaho, Montana, Wyoming.	Physaria carinata
69	Fruits cordate to obdeltate, obcordate, or obovate; California, Idaho, Nevada, Utah	> 70
70	Fruiting pedicels recurved; fruits obdeltate, usually pendent; septums nearly obsolete.	Physaria obdeltata
70	Fruiting pedicels spreading, sigmoid, or recurved; fruits obcordate to obdeltate, not pendent; septums complete	> 71
71	Fruiting pedicels sigmoid; fruits strongly flattened; racemes sometimes elongated.	Physaria cordiformis
71	Fruiting pedicels spreading, or, occasionally, loosely sigmoid or recurved; fruits slightly flattened; racemes not elongated (dense, congested).	Physaria hemiphysaria
72	Annuals or, rarely, biennials.	Physaria tenella
72	Perennials	> 73
73	Fruit valves sparsely pubescent or glabrous; plants of arctic and boreal regions of Canada and Greenland.	Physaria arctica
73	Fruit valves ± densely pubescent; plants usually of the continental United States (P. spatulata occurring to sw Canada)	> 74
74	Fruiting pedicels recurved (P. lesicae sometimes with many pedicels arching); fruits pendent	> 75
74	Fruiting pedicels usually not recurved (sigmoid, horizontal, divaricate-ascending, ascending, or spreading); fruits horizontal to erect	> 80
75	Inner stems erect; fruits: septum complete	> 76
75	Inner stems usually prostrate or decumbent; fruits: septum complete, fenestrate, strongly perforate, or obsolete (except P. parviflora)	> 77
76	Cauline leaves 1-3.5 cm wide, not spreading (somewhat appressed to stem); fruit valves sparsely pubescent; ovules 4-6 per ovary.	Physaria aurea
76	Cauline leaves less than 6(-8) mm wide, spreading; fruit valves densely pubescent; ovules 8-12 per ovary.	Physaria pendula
77	Fruits: septum complete; ovules 4 per ovary; nw Colorado.	Physaria parviflora
77	Fruits: septum fenestrate, perforate, or obsolete; ovules 4-12(-16) per ovary; Arizona, California, Idaho, Nevada, Oregon, Utah, Wyoming	> 78
78	Fruits papery, strongly inflated; basal leaf blades orbicular to broadly obovate, abruptly narrowing to petioles.	Physaria macrocarpa
78	Fruits rigid, not or slightly inflated; basal leaf blades elliptic, rhombic, ovate, suborbicular, or broadly oblanceolate to broadly elliptic, or rhombic, gradually tapering to petioles	> 79
79	Fruits sometimes slightly obcompressed; styles 1-2 mm; racemes secund.	Physaria fremontii
79	Fruits slightly compressed (angustiseptate); styles 2.4-9 mm; racemes usually not secund.	Physaria kingii
80	Fruit valves: trichome rays strongly ascending, spreading (appearing fuzzy).	Physaria klausii
80	Fruit valves: trichome rays appressed or somewhat spreading	> 81
81	Fruits globose, (1-)2-2.8 mm; styles 2-3.5(-4) mm.	Physaria globosa
81	Fruits globose, subglobose, orbicular, suborbicular, ovoid, obovoid, lanceolate, ellipsoid, or obpyriform, (2.5-)3-12 mm; styles 1.5-9 mm	> 82
82	Basal leaf blades broadly elliptic to suborbicular, distinctly rhombic, or deltate, petioles well-differentiated from blades	> 83
82	Basal leaf blades ± spatulate, narrowly oblanceolate, or elliptic (if wider, blades gradually tapering to petioles), petioles usually weakly differentiated from blades	> 89
83	Stems prostrate or decumbent	> 84
83	Stems (inner) ascending to erect	> 85
84	Fruits wider than long, sparsely pubescent inside; Bitterroot Mountains, Montana.	Physaria humilis
84	Fruits longer than wide, glabrous or sparsely pubescent inside; Idaho, Utah, sw Wyoming.	Physaria prostrata
85	Racemes lax, elongated; fruits not compressed apically	> 86
85	Racemes dense, (subcorymbose to subumbellate, few-flowered); fruits compressed apically	> 87
86	Stems to 4.5 dm; basal leaf blades: margins entire, sinuate, coarsely dentate, or lyrate-pinnatifid.	Physaria douglasii
86	Stems 1-1.5 dm; basal leaf blades: margins entire.	Physaria lesicae
87	Basal leaf blades rhombic; sw Colorado, ne Utah, sw Wyoming.	Physaria subumbellata
87	Basal leaf blades oblanceolate to orbicular (usually noticeably thickened)	> 88
88	Fruits with slight apical constriction; Pryor Mountains, Montana.	Physaria pachyphylla
88	Fruits compressed at margins, rounded apically; Arizona.	Physaria cinerea
89	Fruits often somewhat compressed, elliptic to lanceolate, apices ± acute	> 90
89	Fruits compressed or not, subglobose to ovoid (rarely obdeltate), apices rounded, truncate, or obtuse	> 92
90	Sepals 5-8.5 mm, median pair cucullate at apex; petals narrowly spatulate to obovate; ovules (8-)12-20(-24) per ovary.	Physaria montana
90	Sepals 3.5-5 mm, median pair not cucullate at apex; petals lingulate to narrowly oblanceolate; ovules 4-8 per ovary	> 91
91	Fruiting pedicels 4-7 mm; styles shorter than fruits.	Physaria curvipes
91	Fruiting pedicels 10-20 mm; styles ± equal to fruits.	Physaria spatulata
92	Fruit valves: trichomes spreading rays (appearing fuzzy).	Physaria garrettii
92	Fruit valves: trichomes appressed rays	> 93
93	Fruits inflated, slightly didymous, becoming purplish; sw Colorado.	Physaria scrotiformis
93	Fruits not inflated, not didymous, remaining greenish; Arizona, California, Idaho, Nevada, New Mexico, Oregon, Texas, Utah, Wyoming	> 94
94	Caudices thickened; fruit apices somewhat compressed.	Physaria valida
94	Caudices not thickened; fruit apices not compressed (or fruits slightly compressed throughout)	> 95
95	Basal leaves with relatively long, slender petioles; sw New Mexico.	Physaria lata
95	Basal leaves with relatively short, stout petioles; Arizona, California, Idaho, Nevada, Oregon, Utah, Wyoming	> 96
96	Caudices simple; ovules 4-16 per ovary.	Physaria kingii
96	Caudices branched (underground); ovules usually 4 per ovary.	Physaria multiceps