Packera tridenticulata |
Packera musiniensis |
|
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threetooth ragwort |
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|
Habit | Perennials, 10–30+ cm; taprooted (caudices ascending to erect). | Perennials, 5–10 cm; ± rhizomatous (bases loosely branched, elongated, horizontal to ascending). |
Stems | 1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose. |
1 (sometimes branched from bases), densely white- or gray-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). |
petiolate; blades oblanceolate, 20–30+ × 5–13+ mm, bases tapering, margins pinnatifid to crenate. |
Cauline leaves | gradually reduced (± petiolate or sessile). |
gradually reduced (sessile; proximal and mid nearly equaling basals, distals bractlike). |
Peduncles | bracteate, glabrous or sparsely tomentose. |
ebracteate, tomentose. |
Ray florets | 8–10(–13); corolla laminae 5–8+ mm. |
0 or 1; corolla laminae ca. 6 mm. |
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. |
8–13, yellow-green to purple (or with purplish midstripes), 8–9.5 mm, sparsely tomentose (apices rounded). |
Calyculi | inconspicuous. |
0 or inconspicuous. |
Heads | 4–15+ in corymbiform arrays. |
3–15+ 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. |
= 46. |
Packera tridenticulata |
Packera musiniensis |
|
Phenology | Flowering late May–early Jul. | Flowering mid Jul–mid Aug. |
Habitat | Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs | Subalpine and alpine ridges, talus or scree slopes, barren areas on Flagstaff limestone |
Elevation | 1000–2000 m (3300–6600 ft) | 2900–3300 m (9500–10800 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 musiniensis is a high-elevation dwarf species; its affinities within Packera are still uncertain. Welsh believed it to be allied to P. cana or P. multilobata, or both. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 601. | FNA vol. 20, p. 592. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus | Senecio musiniensis |
Name authority | (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) | (S. L. Welsh) Trock: Sida 21: 1643. (2005) |
Web links |