Packera tridenticulata |
Packera castoreus |
|
---|---|---|
threetooth ragwort |
beaver mountain ragwort |
|
Habit | Perennials, 10–30+ cm; taprooted (caudices ascending to erect). | Perennials, 3–9+ cm; usually fibrous-rooted, sometimes rhizomatous (bases erect or ascending, branched). |
Stems | 1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose. |
1 or 2–3, (white) woolly-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). |
(and proximal cauline) petiolate; blades obovate to oblanceolate or spatulate, 10–20+ × 5–18 mm, bases tapering, margins entire or crenate (abaxial faces densely tomentose, adaxial glabrescent). |
Cauline leaves | gradually reduced (± petiolate or sessile). |
gradually reduced (becoming sessile and bractlike). |
Peduncles | bracteate, glabrous or sparsely tomentose. |
ebracteate. |
Ray florets | 8–10(–13); corolla laminae 5–8+ mm. |
0. |
Disc florets | 45–60+; corolla tubes 3–3.5 mm, limbs 4–5 mm. |
not seen. |
Phyllaries | 13 or 21, green, 6–10 mm, sparsely tomentose proximally, glabrous distally. |
purple-tinged, 7–10 mm, tomentose (ciliate distally, apices with dense tufts of hairs). |
Calyculi | inconspicuous. |
inconspicuous. |
Heads | 4–15+ in corymbiform arrays. |
1–4+, in corymbiform arrays. |
Cypselae | 1.5–2.5 mm, glabrous or sparsely hirtellous on ribs; pappi 5–6 mm. |
not seen (reported to be glabrous). |
2n | = 46. |
|
Packera tridenticulata |
Packera castoreus |
|
Phenology | Flowering late May–early Jul. | Flowering late Jul–late Sep. |
Habitat | Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs | Ridges, spruce-fir communities, igneous soils |
Elevation | 1000–2000 m (3300–6600 ft) | 3300–3900 m (10800–12800 ft) |
Distribution |
CO; KS; ND; NE; NM; OK; SD; TX; WY
|
UT |
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 castoreus is known only from relatively few collections from the Tushar Mountains in Beaver and Piute counties. Welsh speculated that it may have some affinities with P. cana and P. werneriifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 601. | FNA vol. 20, p. 582. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus | Senecio castoreus |
Name authority | (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) | (S. L. Welsh) Kartesz: in J. T. Kartesz and C. A. Meacham, Synth. N. Amer. Fl., nomencl. innov. 20. (1999) |
Web links |