Perennials, 10-30+ cm; taprooted (caudices ascending to erect). Stems 1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose. Basal leaves (and proximal cauline, relatively thick and turgid) petiolate; blades lanceolate or narrowly oblanceolate, 20-40+ × 5-15 mm, bases tapering, margins usually entire, sometimes sub-pinnatisect (apices subentire or dentate). Cauline leaves gradually reduced (± petiolate or sessile). Heads 4-15+ in corymbiform arrays. Peduncles bracteate, glabrous or sparsely tomentose. Calyculi incon-spicuous. Phyllaries 13 or 21, green, 6-10 mm, sparsely tomentose proximally, glabrous distally. Ray florets 8-10(-13); corolla laminae 5-8+ mm. Disc florets 45-60+; corolla tubes 3-3.5 mm, limbs 4-5 mm. Cypselae 1.5-2.5 mm, glabrous or sparsely hirtellous on ribs; pappi 5-6 mm. 2n = 46.

Flowering late May-early Jul. Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs; 1000-2000 m; Colo., Kans., Nebr., N.Mex., N.Dak., Okla., S.Dak., Tex., Wyo.

Packera tridenticulata is found throughout the central High Plains, in the foothills of the Rocky Mountains, and in high valleys to the west of the Rocky Mountain front. It tends to grow in clumps; the multiple stems arise from well-developed taproots. It apparently hybridizes with P. neomexicana var. mutabilis where their ranges overlap.

Duration: Perennial

Nativity: Native

Lifeform: Forb/Herb

General: Herbaceous to shrubby perennials, to 30 cm tall, stems 1 to many, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose, caudices ascending to erect, plants taprooted.

Leaves: Alternate, basal leaves relatively thick and turgid, lanceolate to narrowly oblanceolate, to 40 mm long and 15 mm wide, bases tapering, margins usually entire, sometimes sub-pinnatisect, apices subentire or dentate, petiolate, cauline leaves reduced.

Flowers: Heads somewhat large and showy, radiate, rays yellow, 8-13, disk flowers yellow, many, involucre of 1 series, with inconspicuous row of bracts around outer calyx, phyllaries 13 to 21, green, 6-10 mm long, sparsely tomentose proximally, glabrous distally, heads in groups of 4-15 or more, borne in corymbiform arrays.

Fruits: Achenes 1.5-2.5 mm long, glabrous or sparsely hirtellous on the ribs. Pappus of soft, white, capillary bristles 5-6 mm long.

Ecology: Found in open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs, from 3,500-7,000 ft (1067-2134 m); flowering May-July.

Distribution: Colorado, Kansas, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Wyoming.

Ethnobotany: Unknown

Etymology: Packera is named for John G. Packer (1929-) a contemporary botanist, while tridenticulata means with three dentate teeth.

Synonyms: Several, see Tropicos

Editor: LCrumbacher 2011