Ericameria nauseosa var. iridis
Ericameria nauseosa
Rainbow Hills rabbitbrush
chamisa, common rabbit-brush, gray rabbitbrush, rabbitbrush, rubber rabbitbrush
grayish green (at least when young), leafy, faces ± compactly tomentose.
erect or ascending to spreading, white to green, fastigiately branched, tomentose.
grayish green;
blades 1-nerved, linear, 15–40 × 0.8–1 mm, compactly tomentose.
(usually crowded) usually ascending to spreading;
blades filiform to narrowly oblanceolate (mostly adaxially sulcate to concave), 10–70 × 0.3–10 mm, midnerves mostly evident, apices acute, faces glabrous or tomentose, often gland-dotted (lacking well-defined circular pits);
axillary fascicles absent.
1–20 mm (bracts usually 0, sometimes 1–5, reduced, scalelike).
12–16 mm.
obconic to subcylindric, 6–16 × 2–4 mm.
0.
(4–)5(–6);
corollas 6–12 mm.
7.8–8.7 mm, tubes glabrous, lobes 1.5–2 mm, glabrous;
style appendages longer than stigmatic portions.
20–26, apices erect, acute to acuminate, abaxial faces glabrous.
10–31 in 3–5 series (often in vertical ranks), tan, ovate to lanceolate, 1.5–14 × 0.7–1.5 mm, strongly unequal, mostly chartaceous (mostly keeled), midnerves raised for nearly entire lengths, expanded apically, apices acute to obtuse, abaxial faces resinous.
in rounded to flat-topped, cymiform arrays (to 12 cm wide).
glabrous;
pappi 5.2–5.8 mm.
tan, turbinate to cylindric or oblanceoloid, 3–8 mm, glabrous or hairy (often ± pilose or sericeous);
pappi whitish, 3–13 mm.
= 18.
= 18.
Ericameria nauseosa var. iridis
Ericameria nauseosa
Of conservation concern.
Variety iridis is known only from Sevier County.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 21 (21 in the flora).
Ericameria nauseosa is widespread, often abundant, and complex. This treatment is based largely on that by L. C. Anderson (1986b). Uncertainty about the specimen used by Pursh to establish E. nauseosa (as Chrysocoma nauseosa) is a possible source of confusion concerning the application of that name (which is in current use) and of the name Chrysothamnus speciosus Nuttall (J. L. Reveal et al. 1999). Anderson divided the species into two informal groups, the “green forms” and the “gray forms.” These two groups were formalized as subspp. nauseosa and consimilis by G. L. Nesom and G. I. Baird (1993), each containing varieties. Ericameria nauseosa is reported to hybridize with other species in the genus, and hybrid and formula names have been applied to them. Their synonymies were more fully summarized by Nesom and Baird.
Ericameria ×bolanderi (A. Gray) G. L. Nesom & G. I. Baird, based on Linosyris bolanderi A. Gray is the hybrid between E. discoidea and E. nauseosa (L. C. Anderson and J. L. Reveal 1966).
Ericameria ×uintahensis (L. C. Anderson) G. L. Nesom & G. I. Baird, “Uinta rubber rabbitbrush,” based on Chrysothamnus nauseosus subsp. uintahensis L. C. Anderson, is the hybrid between E. nauseosa and E. parryi (L. C. Anderson 1984).
Ericameria ×viscosa (D. D. Keck) G. L. Nesom & G. I. Baird, based on Chrysothamnus nauseosus subsp. viscosus D. D. Keck, is the hybrid between E. cuneata and E. nauseosa (L. C. Anderson 1986b).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Cypselae glabrous | → 2 |
1. Cypselae hairy (± pilose or sericeous, only distally in var. washoensis) | → 11 |
2. Style appendages shorter than or equaling stigmatic portions | → 3 |
2. Style appendages longer than stigmatic portions | → 4 |
3. Corolla lobes 1.5–2.5 mm | var. oreophila |
3. Corolla lobes 0.6–1.3 mm; Guadalupe Mountains, New Mexico, Texas | var. texensis |
4. Corolla lobes villous | → 5 |
4. Corolla lobes glabrous | → 6 |
5. Plants 60–150 cm; involucres 10–12.5 mm; inner phyllary apices acute to obtuse; sandy gravels of dry streambeds, c, ne Arizona, New Mexico, Utah | var. nitida |
5. Plants 40–60 cm; involucres 11.2–16 mm; inner phyllary apices acute to short-acuminate; dunes and deep sands, nw Arizona, e Nevada, Utah | var. turbinata |
6. Phyllary abaxial faces (at least outer) tomentulose or scurfy-tomentulose | → 7 |
6. Phyllary abaxial faces usually glabrous (outer sometimes sparingly hairy in var. oreophila) | → 8 |
7. Stems nearly leafless (at flowering); leaves 15–30 × 0.5–1 mm; phyllary apices acute to acuminate | var. bigelovii |
7. Stems leafy; leaves 30–50 × 1–1.5 mm; phyllary apices acute (outer) to frequently obtuse (inner) | var. nitida |
8. Stems often leafless (at flowering); phyllary apices acute to obtuse; corolla lobes 0.5–1.1 mm | var. leiosperma |
8. Stems usually leafy; phyllary apices acute, acuminate, or cuspidate; corolla lobes 1.3–2.5+ mm | → 9 |
9. Plants 10–20 cm; involucres 12–16 mm; gypsiferous shale, Sevier County, Utah | var. iridis |
9. Plants 25–250 cm; involucres 6.5–12.5 mm; w United States (not on highly gypsiferous soils) | → 10 |
10. Corolla lobes 1.3–1.5 mm; leaves 1–2 mm wide; ec Utah | var. psilocarpa |
10. Corolla lobes 1.5–2.5 mm; leaves 0.8–1 mm wide; w UnitedStates | var. oreophila |
11. Style appendages usually shorter than stigmatic portions (equaling or shorter in var. lastisquamea, about equaling in var. oreophila) | → 12 |
11. Style appendages longer than stigmatic portions | → 16 |
12. Corolla lobes 0.5–1 mm | → 13 |
12. Corolla lobes 1.5–2.5 mm | → 14 |
13. Phyllaries tomentose; well-drained, gravelly or sandy slopes; c, w Arizona, s California, s Idaho, Nevada, New Mexico, se Oregon, Utah | var. hololeuca |
13. Outer phyllaries densely tomentulose, inner glabrous; dry streambeds and arroyos; se Arizona, New Mexico | var. latisquamea |
14. Phyllary apices recurved (s California) | var. ceruminosa |
14. Phyllary apices erect | → 15 |
15. Plants 10–30 cm; leaf blades 1–3 mm wide; Idaho, Oregon, Washington | var. nana |
15. Plants 70–250 cm; leaf blades 0.8–1 wide; w United States | var. oreophila |
16. Corolla lobes villous (sometimes sparsely) | → 17 |
16. Corolla lobes glabrous | → 20 |
17. Cypselae distally pilose; corolla lobes 1.3–1.6 mm; ne California, adjacent Nevada | var. washoensis |
17. Cypselae hairy throughout; corolla lobes 0.7–0.9 mm; Arizona, c, s Nevada, Utah | → 18 |
18. Stems usually leafless (at flowering); co-rollas 7–8.5 mm | var. juncea |
18. Stems at least moderately leafy; corollas 9.5–11.8 mm | → 19 |
19. Leaf blades 30–50 mm, faces glabrate; inner phyllary apices acute to obtuse; corolla lobes glabrous or villous; northern Arizona, ne New Mexico,s Utah | var. nitida |
19. Leaf blades 10–20 mm, faces tomentulose to densely tomentose; inner phyllary apices usually acute to acuminate; corolla lobes villous; e Nevada, Utah | var. turbinata |
20. Involucres 16–19 mm; phyllary apices ± recurved | var. arenaria |
20. Involucres 6–14.5 mm; phyllary apices erect | → 21 |
21. Stems nearly leafless (at flowering; s California, s Nevada) | var. mohavensis |
21. Stems leafy | → 22 |
22. Leaf blades 3–5-nerved, 3–6(–10) mm wide (mountains, Utah, Cache to Sevier counties) | var. salicifolia |
22. Leaf blades 1–3-nerved, 0.3–3 mm wide | → 23 |
23. Phyllaries usually glabrous, outer sometimes sparsely hairy | → 24 |
23. Phyllaries usually hairy (at least outer, sometimes ± tomentose), rarely glabrous | → 26 |
24. Corollas 10–12 mm; involucres 10–14 mm (s California) | var. bernardina |
24. Corollas 6–9+ mm; involucres 6–10 mm | → 25 |
25. Corolla lobes 0.6–1.5 mm; corolla tubes puberulent or glabrous; plains, Arizona, Utah, Wyoming eastward | var. graveolens |
25. Corolla lobes 1.5–2.5 mm; corolla tubes glabrous; Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, w Wyoming | var. oreophila |
26. Involucres 6–10 mm; corollas 6–9 mm | → 27 |
26. Involucres 7.5–14 mm; corollas 8.7–13 mm | → 28 |
27. Corolla tubes usually puberulent, rarely arachnose; plains and hills, Alberta, Saskatchewan, Colorado, Idaho, Montana, Nebraska, North Dakota, South Dakota, Wyoming | var. nauseosa |
27. Corolla tubes glabrous; Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, w Wyoming (mostly Great Basin) | var. oreophila |
28. Inner phyllary apices acute to obtuse; corolla lobes 0.7–1 mm (n Arizona, ne New Mexico, s Utah) | var. nitida |
28. Inner phyllary apices acuminate to acute; corolla lobes 1.1–2.3 mm | → 29 |
29. Stems yellowish green, becoming whitish, compactly tomentose; leaves yellowish green (s California) | var. bernardina |
29. Stems whitish, loosely tomentose; leaves dark green to grayish white | var. speciosa |
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