Perennials, 60-100+ cm; taprooted (caudices subligneous, ascending to erect). Stems 1 or 2-4, clustered (proximally deeply purple-tinged, distally lightly tinged), glabrous or tomentose at bases and in leaf axils. Basal leaves (and proximal cauline) petiolate; blades obovate or lyrate (pinnately lobed, lateral lobes 2-6+ pairs, their bases petioluliform, terminal lobes larger than laterals, midribs narrowly winged), 60-160+ × 20-40+ mm, bases wide, ultimate margins sharply dentate, crenate-dentate, or irregularly incised. Cauline leaves gradually reduced (petiolate or sessile; shallowly lobed, midribs ± winged, distals bractlike, dentate to incised). Heads 15-40+ in open, cymiform arrays. Peduncles ebracteate, glabrous. Calyculi inconspicuous. Phyllaries (13-)21, green (tips yellow), 5-7 mm, glabrous (tips sometimes hairy). Ray florets (8-)13; corolla laminae 6-10+ mm. Disc florets 60-70+; corolla tubes 2-3 mm, limbs 3.5-4.5 mm. Cypselae 1.5-2 mm, glabrous or ± scabrellous; pappi 5.5-6.5 mm. 2n = 92.
Flowering mid Apr-early Jun. Rocky soils, open areas, scrub-oak and pinyon-pine forests, chaparral; 800-2200 m; Ariz., N.Mex.
Packera quercetorum is found only infrequently and in relatively small populations in central and southern Arizona and west-central New Mexico. The plants are robust and have probable affinities to P. multilobata. The plants have a bluish tinge when freshly collected and are distinctive in the field.
Duration: Perennial
Nativity: Native
Lifeform: Forb/Herb
General: Taprooted perennial with erect to ascending stems 60-100 cm tall, usually clustered with 2-4 stems, deeply purple-tinged, glabrous or tomentose at bases and in leaf axils.
Leaves: Basal leaves petiolate, blades obovate or lyrate, pinnately lobed, lateral lobes 2-6 pairs, terminal lobes larger than laterals, 60-160 mm long by 20-40 mm wide, bases wide, with ultimate margins sharply dentate, to irregularly incised.
Flowers: Heads 15-40+ in open, cymiform arrays, on ebracteate peduncles, glabrous; phyllaries 21, green with yellow tips, 5-7 mm, glabrous although tips are sometimes hairy; ray florets 13, corolla laminae 6-10 mm, disc florets 60-70+, corolla tubes 2-3 mm, limbs 3.5-4.5 mm.
Fruits: Cypselae 1.5-2 mm, glabrous to more or less scabrellous, with pappus 5.5-6.5 mm.
Ecology: Found on rocky soils, often in open areas in scrub oak and chaparral from 2,500-7,500 ft (762-2286 m); flowers April-June.
Notes: The purplish blue tinge is distinctive with this plant, as is its size and distinctive basal leaves with tomentose leaf axils.
Ethnobotany: Unknown
Etymology: Packera is named for John G. Packer (1929-) a contemporary botanist, while quercetorum means of oak woods.
Synonyms: Senecio quercetorum
Editor: SBuckley, 2010
