Packera quercetorum (Greene) C. Jeffrey

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.

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.

Senecio quercetorum Greene, Leafl. Bot. Observ. Crit. 2: 20. 1909; S. macropus Greenman

Senecio quercetorum adalah spesies tumbuhan yang tergolong ke dalam famili Asteraceae. Spesies ini juga merupakan bagian dari ordo Asterales. Spesies Senecio quercetorum sendiri merupakan bagian dari genus Senecio. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh Greene.

Packera quercetorum là một loài thực vật có hoa trong họ Cúc. Loài này được (Greene) C.Jeffrey mô tả khoa học đầu tiên năm 1992.