Packera tridenticulata
Packera antennariifolia
threetooth ragwort
shale barren ragwort
1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose.
1 (sometimes from rosettes, rosettes sometimes clustered), tomentose.
(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).
petiolate;
blades broadly lanceolate to elliptic or spatulate, 20–40+ × 10–20+ mm, bases tapering, margins entire or subentire to dentate distally (faces tomentose).
gradually reduced (± petiolate or sessile).
abruptly reduced (petiolate or sessile; narrowly lanceolate to sublyrate, sharply toothed to pinnatisect or entire).
bracteate, glabrous or sparsely tomentose.
bracteate, densely lanate to sparsely tomentose.
8–10(–13);
corolla laminae 5–8+ mm.
8–10(–13);
corolla laminae 5–10 mm.
45–60+;
corolla tubes 3–3.5 mm, limbs 4–5 mm.
25–35+;
corolla tubes 3–4 mm, limbs 1.5–2 mm.
13 or 21, green, 6–10 mm, sparsely tomentose proximally, glabrous distally.
13 or 21, green, 5–7 mm, densely tomentose (apices scarious).
inconspicuous.
inconspicuous.
4–15+ in corymbiform arrays.
6–12+ in corymbiform arrays (lateral cymiform arrays sometimes originating in leaf axils).
1.5–2.5 mm, glabrous or sparsely hirtellous on ribs;
pappi 5–6 mm.
1–1.5 mm, hirtellous on ribs;
pappi 4–5 mm.
= 46.
= 46.
Packera tridenticulata
Packera antennariifolia
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Packera antennariifolia is known only from shale barrens or shale-derived soils in central Appalachia. Plants growing on steep slopes have stouter, more horizontal caudices and more extensive fibrous roots than specimens from other locations. Specimens from shale-derived soils, not growing directly on shale barrens, have weakly lobulate leaves and noticeably less hairiness.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
KS Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
MD Biodiversity
