Packera tridenticulata |
Packera quercetorum |
|
---|---|---|
threetooth ragwort |
Oak Creek ragwort |
|
Habit | Perennials, 10–30+ cm; taprooted (caudices ascending to erect). | Perennials, 60–100+ cm; taprooted (caudices subligneous, ascending to erect). |
Stems | 1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose. |
1 or 2–4, clustered (proximally deeply purple-tinged, distally lightly tinged), glabrous or tomentose at bases and in leaf axils. |
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 or lyrate (pinnately lobed, lateral lobes 2–6+ pairs, their bases petioluliform, terminal lobes larger than laterals, midribs narrowly winged), 60–160+ × 20–40+ mm, bases wide, ultimate margins sharply dentate, crenate-dentate, or irregularly incised. |
Cauline leaves | gradually reduced (± petiolate or sessile). |
gradually reduced (petiolate or sessile; shallowly lobed, midribs ± winged, distals bractlike, dentate to incised). |
Peduncles | bracteate, glabrous or sparsely tomentose. |
ebracteate, glabrous. |
Ray florets | 8–10(–13); corolla laminae 5–8+ mm. |
(8–)13; corolla laminae 6–10+ mm. |
Disc florets | 45–60+; corolla tubes 3–3.5 mm, limbs 4–5 mm. |
60–70+; corolla tubes 2–3 mm, limbs 3.5–4.5 mm. |
Phyllaries | 13 or 21, green, 6–10 mm, sparsely tomentose proximally, glabrous distally. |
(13–)21, green (tips yellow), 5–7 mm, glabrous (tips sometimes hairy). |
Calyculi | inconspicuous. |
inconspicuous. |
Heads | 4–15+ in corymbiform arrays. |
15–40+ in open, cymiform arrays. |
Cypselae | 1.5–2.5 mm, glabrous or sparsely hirtellous on ribs; pappi 5–6 mm. |
1.5–2 mm, glabrous or ± scabrellous; pappi 5.5–6.5 mm. |
2n | = 46. |
= 92. |
Packera tridenticulata |
Packera quercetorum |
|
Phenology | Flowering late May–early Jul. | Flowering mid Apr–early Jun. |
Habitat | Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs | Rocky soils, open areas, scrub-oak and pinyon-pine forests, chaparral |
Elevation | 1000–2000 m (3300–6600 ft) | 800–2200 m (2600–7200 ft) |
Distribution |
CO; KS; ND; NE; NM; OK; SD; TX; WY
|
AZ; NM
|
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.) |
Packera quercetorum is found only infrequently and in relatively small populations in central and southern Arizona and west-central New Mexico. The plants are robust and have probable affinities to P. multilobata. The plants have a bluish tinge when freshly collected and are distinctive in the field. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 601. | FNA vol. 20, p. 598. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus | Senecio quercetorum, Senecio macropus |
Name authority | (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) | (Greene) C. Jeffrey: Kew Bull. 47: 101. (1992) |
Web links |