Packera tridenticulata |
Packera millefolium |
|
---|---|---|
threetooth ragwort |
Piedmont ragwort |
|
Habit | Perennials, 10–30+ cm; taprooted (caudices ascending to erect). | Perennials, 25–60+ cm; fibrous-rooted (caudices branched). |
Stems | 1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose. |
1 or 2–3, clustered, glabrous or leaf axils sparsely hairy. |
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). |
(and proximal cauline) petiolate; blades narrowly ovate to ovate (2–3 times pinnately dissected, ultimate lobes mostly linear to filiform), 50–80 × 30–50 mm, bases ± truncate or auriculate, ultimate margins entire or remotely dentate. |
Cauline leaves | gradually reduced (± petiolate or sessile). |
gradually reduced (petiolate or sessile, similar to basals). |
Peduncles | bracteate, glabrous or sparsely tomentose. |
bracteate or ebracteate, glabrous. |
Ray florets | 8–10(–13); corolla laminae 5–8+ mm. |
8–10(–13); corolla laminae 8–12 mm. |
Disc florets | 45–60+; corolla tubes 3–3.5 mm, limbs 4–5 mm. |
35–50+; corolla tubes 2–3 mm, limbs 1.5–2.5 mm. |
Phyllaries | 13 or 21, green, 6–10 mm, sparsely tomentose proximally, glabrous distally. |
(13–)21, green, 4–6 mm, glabrous (tips sometimes hair-tufted). |
Calyculi | inconspicuous. |
0. |
Heads | 4–15+ in corymbiform arrays. |
10–30+ in open, corymbiform arrays. |
Cypselae | 1.5–2.5 mm, glabrous or sparsely hirtellous on ribs; pappi 5–6 mm. |
0.75–1.5 mm, hairy on ribs; pappi 3–4 mm. |
2n | = 46. |
|
Packera tridenticulata |
Packera millefolium |
|
Phenology | Flowering late May–early Jul. | Flowering early May–mid Jun. |
Habitat | Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs | Open areas along streams, rock outcrops in thin, granitic-derived soils |
Elevation | 1000–2000 m (3300–6600 ft) | 400–900 m (1300–3000 ft) |
Distribution |
CO; KS; ND; NE; NM; OK; SD; TX; WY
|
GA; NC; SC; VA |
Discussion | 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.) |
Of conservation concern. Packera millefolia is known only from granitic soils in the southern Appalachians. It is similar in overall aspect to the widespread P. anonyma; it differs by its 2–3 times pinnately dissected leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 601. | FNA vol. 20, p. 591. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus | Senecio millefolium, Senecio memmingeri |
Name authority | (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) | (Torrey & A. Gray) W. A. Weber & Á. Löve: Phytologia 49: 47. (1981) |
Web links |