Psorothamnus emoryi (A. Gray) Rydb.
Fabaceae (Pea family)
Synonym(s): Dalea emoryi
USDA Symbol: PSEM
"Early suffrutescent herbs, rarely flowering prematurely as herbaceous annuals, commonly becoming rounded shrubs or subshrubs 3-10 dm tall and up to twice as wide, most often densely and softly tomentulose throughout with fine, spreading or subretrorse, ± entangled hairs up to ± 0.2-0.4 mm long, rarely the stems alone or both stems and foliage together glabrescent to fully glabrous, these then deep green and dotted all over with reddish-orange glands (always present, but here revealed), the foliage drought-deciduous, the plant becoming in dry seasons ± junceous and cancellate." (bibref: 1812).
"At anthesis in late spring and early summer on the floor of the Colorado Desert, P. e. var. emoryi is a showy small shrub, often wider than tall, covered all over with countless fluffy balls of rosy-purple flower. Later in the year the foliage disjoints, leaving only a dense tangle of gray interlacing branchlets. North of the border var. emoryi is so densely tomentulose throughout that only a few of the larger orange glands on the stems and peduncles are visible externally, but these are fragile, yielding when bruised a strong-smelling, orange oil." (bibref: 1812).
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Habit: Herb , Subshrub , Shrub
Leaf Arrangement: Alternate
Size Notes: "3-10 dm tall." (bibref: 1812).
Leaf: "Leaf-spurs almost 0; stipules subulate, 0.6-1.1 mm long, commonly tomentulose, charged on margins with a pair of orange glands, caducous; intra-petiolular glands 0; post-petiolular glands small but prominent, sometimes concealed by woolly vesture; leaves polymorphic and variable both from one plant to another and according to position on the stem, the main cauline ones usually with 2-4 (6) pairs of lateral leaflets varying from suborbicular-emarginate to oblong-oblanceolate or elliptic and from 2 to 10 mm long, the terminal leaflet always longer, usually narrower, obovate to oblanceolate or sublinear, mostly 4-16 (20) mm long, all flat or nearly so, the margins either entire or crenulate-dentate, gland-charged on both faces but the glands often concealed by vesture, the upper (sometimes all) leaves shorter and simpler, 3-foliolate or reduced to a subsessile blade, the uppermost often minute and bracteiform." (bibref: 1812).
Flower: "Peduncles leaf-opposed and terminal to all ultimate branchlets, 0.5-12 m long; spikes dense, mostly capitate and subglobose, rarely oblong, without petals 7.5-13 (15) mm diameter, the pilosulous axis becoming (1) 3-20 mm long; bracts early deciduous, narrowly lance-elliptic or subulate to sublinear, 1.5-3 mm long, pilosulous dorsally, the margins usually charged with 1-3 pairs of subulate orange glands; pedicels 0 (rarely to 0.2 mm long); bracteoles represented by 2 minute orange spicules; calyx (2.7) 3-6.6 (7.2) mm long, pilosulous with fine weak ascending hairs up to 0.4-0.8 mm long, the golden-yellow tube 1.7-3.4 mm long, its ribs slender becoming prominent, the intervals charged with 1-2 rows of small orange glands, the 1-nerved teeth varying from lance-acuminate to ovate-triangular and from ±: 1 mm shorter up to 1 mm longer than tube, all gland-tipped and -spurred, the sinus behind the banner sometimes shallower than the rest; petals (deciduous) usually bicolored, the banner-blade margined and the inner petals banded along inner half with vivid purple or violet, otherwise paler or whitish, the blades of banner, keel, and often of wings also, pilosulous externally in distal 1/2-1/3; banner 4.2-6.3 mm long, the claw 1.6-2.3 mm, the ovate-cordate, apically emarginate blade 2.8-4.8 mm long, 2.4-4.1 mm wide, charged near apex dorsally with a prominent blister-gland; wings 5.2-7.8 mm long, the claw 1.6-2.6 mm, the narrowly oblong or oblong-oblanceolate, gland-tipped blade (3.5) 3.8-5.2 mm long, 1.3-1.8 mm wide; keel 5.7-8.5 mm long, the claws 1.7-3.3 mm, the obliquely oblong-obovate or broadly obovate blades 3.7-6.2 mm long, (2) 2.2-2.9 mm wide, usually glandless; androecium 5.7-l.5 mm long, the connective gland-tipped, the anthers 0.5-0.9 mm long; stigma slightly enlarged, subcapitate." (bibref: 1812).
Fruit: "Pod subsymmetrically obovoid-ellipsoid, 2.3-2.8 mm long, cuneately narrowed and glabrous at base, pilosulous and gland-sprinkled distally, the style-base terminal; seed (little known) ± 1.5 mm long, the testa smooth, brown, dull, paler at the hilum and sometimes with a fuscous line above it." (bibref: 1812).
Bloom InformationBloom Color: White , Purple , Violet
Bloom Time: Apr , May , Jun , Sep , Oct , Nov , Dec
Bloom Notes: "Petals (deciduous) usually bicolored, the banner-blade margined and the inner petals banded along inner half with vivid purple or violet, otherwise paler or whitish." (bibref: 1812).
DistributionUSA: AZ , CA
Native Distribution: "Widespread and locally abundant around the northern and western edges of the Sonoran Desert, from Coachella Valley, Riverside County, California southward to and just beyond the boundary between Baja California Norte and Sur, but not extending westward to the Pacific, eastward in California to extreme southeastern Mohave Desert in southeastern San Bernardino County (between Twentynine Palms and Amboy), and to the lower Colorado Valley in eastern Riverside and Imperial counties, thence crossing into the lower Gila valley and vicinity in Yuma and western Pima counties, Arizona and southward in coastal Sonora from the Colorado delta to Puerto Kino and neighboring Isla Tiburon." (bibref: 1812).
Native Habitat: "Dunes, sandy flats, washes, mostly below 350 m, exceptionally up to 760 m near its northern limit and in Salton Depression down to -35 m." (bibref: 1812).
BibliographyBibref 1812 - Daleae imagines : an illustrated revision of Errazurizia Philippi, Psorothamnus Rydberg, Marina Leibmann, and Dalea Lucanus emend. Barneby, including all species of Leguminosae tribe Amorpheae Borissova ever referred to Dalea (1977) Barneby, Rupert C.
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Additional resourcesUSDA: Find Psorothamnus emoryi in USDA Plants
FNA: Find Psorothamnus emoryi in the Flora of North America (if available)
Google: Search Google for Psorothamnus emoryi
MetadataRecord Modified: 2021-04-04
Research By: JAM