OregonFlora: Physaria chambersii vs. Brassicaceae

	Physaria chambersii	Brassicaceae
	Chambers' bladderpod	mustard family
Habit	Plants cespitose, silvery; caudices present.	Herbs, rarely woody subshrubs or shrubs annual, biennial, or perennial; taprooted or with caudices, sometimes rhizomatous; trichomes unicellular, simple, 2–many-rayed, stellate, dendritic, or malpighiaceous; stalked or sessile; multicellular glands with uniseriate or multiseriate stalks present or absent.
Stems	arising laterally, 5–15 cm.	leafy or leafless, sometimes absent.
Leaves		basal and/or cauline; simple or compound; margins entire or variously divided, petiolate or sessile; without stipules.
Basal leaves	obovate to orbicular, 3–6 × 1–2 cm; margins entire or dentate.
Cauline leaves	spatulate, 1–2 cm × 3–6 mm; margins entire.
Inflorescences	fruiting pedicels divaricate, slightly sigmoid, 8–15 mm.	racemes; corymbs, or panicles, sometimes flowers solitary from a basal rosette.
Flowers	sepals narrowly lanceolate, 5–8(9) mm; petals narrowly oblanceolate, 9–12 mm, yellow; claws undifferentiated; ovules 4–12 per ovary; styles (4)6–8 mm.	bisexual, hypogynous, radially or rarely bilaterally symmetric; sepals 4; in 2 decussate pairs, usually free; petals 4, forming a cross, rarely absent; stamens (2 or 4)6; in 2 whorls, tetradynamous, rarely equal in length or in 3 pairs of unequal length; median filaments free or rarely united; anthers dithecal, dehiscing by longitudinal slits; pollen 3(10)-colpate, trinucleate; pistils 1, 2-carpelled; ovaries superior; placentation parietal or rarely apical; septa complete, perforated, or lacking; styles 1; stigmas entire or 2-lobed, nectar glands receptacular.
Fruits	didymous; terete, bases obtuse to subcordate; tips notched, pubescent, retaining seeds after dehiscence; valves keeled and 3-angled on back; flat-sided; bladdery, strongly inflated, 1–1.5 × ~1 cm; replums oblong, obtuse at tip, 4–6 × ~1 mm; narrower than fruits.	typically 2-valved capsules (siliques or silicles), dehiscent or indehiscent; terete, 4-angled, flattened parallel to or perpendicular to septum; replums rounded or rarely winged.
Seeds	not margined.	uniseriately or biseriately arranged in each locule, rarely aseriate, mucilaginous or not when wetted, winged or wingless; cotyledons incumbent or accumbent, conduplicate.
Trichomes	few-rayed, with umbos; rays forked, slightly tuberculate.
2n	=8, 10, 16, 24.

	Physaria chambersii	Brassicaceae
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Loose gravel, clay hillsides, sagebrush, pinyon-juniper communities, steep road banks. Flowering Apr–Jun. 500–1400 m. BR, BW, Owy. CA, NV; southeast to AZ. Native.	Cosmopolitan. 340 genera; 59 genera treated in Flora. This family includes many economically important crop plants that are grown as vegetables, sources of vegetable oils (canola), or condiments (table mustard, horseradish, wasabi), or ornamentals. It also includes some 130 species of weeds, including Arabidopsis thaliana, a model organism in experimental and molecular biology. The limits of Brassicaceae (Cruciferae) have not changed in the past two centuries because of characteristic floral and fruit morphology. Generic delimitation within the family is often difficult because of the reliance on fruit characters to separate genera. The ovule number per ovary is a taxonomically important character, which can easily be determined by counting the number of seeds and aborted ovules in the mature fruit. The use of seed number alone may be taxonomically unreliable because many ovules fail to develop into seeds, especially late in the season due to the lack of sufficient pollen.
Source	Flora of Oregon, volume 2, page 501 Ihsan Al-Shehbaz	Flora of Oregon, volume 2, page 434
Sibling taxa	P. douglasii, P. geyeri, P. kingii, P. occidentalis, P. oregona
Web links	Local floras: CA, OR Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Brassicaceae

Chambers' bladderpod

mustard family

Habit

Plants cespitose, silvery; caudices present.

Herbs, rarely woody subshrubs or shrubs annual, biennial, or perennial; taprooted or with caudices, sometimes rhizomatous; trichomes unicellular, simple, 2–many-rayed, stellate, dendritic, or malpighiaceous; stalked or sessile; multicellular glands with uniseriate or multiseriate stalks present or absent.

Stems

arising laterally, 5–15 cm.

leafy or leafless, sometimes absent.

Leaves

basal and/or cauline; simple or compound;

margins entire or variously divided, petiolate or sessile; without stipules.

Basal leaves

obovate to orbicular, 3–6 × 1–2 cm;

margins entire or dentate.

Cauline leaves

spatulate, 1–2 cm × 3–6 mm;

margins entire.

Inflorescences

fruiting pedicels divaricate, slightly sigmoid, 8–15 mm.

racemes; corymbs, or panicles, sometimes flowers solitary from a basal rosette.

Flowers

sepals narrowly lanceolate, 5–8(9) mm;

petals narrowly oblanceolate, 9–12 mm, yellow;

claws undifferentiated;

ovules 4–12 per ovary;

styles (4)6–8 mm.

bisexual, hypogynous, radially or rarely bilaterally symmetric;

sepals 4; in 2 decussate pairs, usually free;

petals 4, forming a cross, rarely absent;

stamens (2 or 4)6; in 2 whorls, tetradynamous, rarely equal in length or in 3 pairs of unequal length;

median filaments free or rarely united;

anthers dithecal, dehiscing by longitudinal slits;

pollen 3(10)-colpate, trinucleate;

pistils 1, 2-carpelled;

ovaries superior;

placentation parietal or rarely apical;

septa complete, perforated, or lacking;

styles 1;

stigmas entire or 2-lobed, nectar glands receptacular.

Fruits

didymous; terete, bases obtuse to subcordate;

tips notched, pubescent, retaining seeds after dehiscence;

valves keeled and 3-angled on back; flat-sided; bladdery, strongly inflated, 1–1.5 × ~1 cm; replums oblong, obtuse at tip, 4–6 × ~1 mm; narrower than fruits.

typically 2-valved capsules (siliques or silicles), dehiscent or indehiscent; terete, 4-angled, flattened parallel to or perpendicular to septum; replums rounded or rarely winged.

Seeds

not margined.

uniseriately or biseriately arranged in each locule, rarely aseriate, mucilaginous or not when wetted, winged or wingless;

cotyledons incumbent or accumbent, conduplicate.

Trichomes

few-rayed, with umbos;

rays forked, slightly tuberculate.

=8, 10, 16, 24.

Physaria chambersii

Brassicaceae

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Loose gravel, clay hillsides, sagebrush, pinyon-juniper communities, steep road banks. Flowering Apr–Jun. 500–1400 m. BR, BW, Owy. CA, NV; southeast to AZ. Native.

Cosmopolitan. 340 genera; 59 genera treated in Flora.

This family includes many economically important crop plants that are grown as vegetables, sources of vegetable oils (canola), or condiments (table mustard, horseradish, wasabi), or ornamentals. It also includes some 130 species of weeds, including Arabidopsis thaliana, a model organism in experimental and molecular biology. The limits of Brassicaceae (Cruciferae) have not changed in the past two centuries because of characteristic floral and fruit morphology. Generic delimitation within the family is often difficult because of the reliance on fruit characters to separate genera. The ovule number per ovary is a taxonomically important character, which can easily be determined by counting the number of seeds and aborted ovules in the mature fruit. The use of seed number alone may be taxonomically unreliable because many ovules fail to develop into seeds, especially late in the season due to the lack of sufficient pollen.

Source

Flora of Oregon, volume 2, page 501
Ihsan Al-Shehbaz

Flora of Oregon, volume 2, page 434

Sibling taxa

P. douglasii, P. geyeri, P. kingii, P. occidentalis, P. oregona

Web links