Artemisia bigelovii |
Artemisia porteri |
|
---|---|---|
Bigelow sage, Bigelow sagebrush, Bigelow sagewort, Bigelow's sage |
Porter mugwort, Porter's wormwood |
|
Habit | Shrubs, 20–40(–60) cm (branched from bases, rounded), mildly aromatic; not root-sprouting. | Perennials or subshrubs, (7–)8–14 cm (cespitose), faintly aromatic. |
Stems | silvery, canescent (bark gray-brown). |
5–8, silver-gray, densely tomentose. |
Leaves | persistent, light gray-green; blades narrowly cuneate, 0.5–3 × 0.2–0.5 cm, entire or 3(–5)-lobed (lobes 1.5–2 mm, less than 1/3 blade lengths, acute), faces silvery canescent. |
persistent, silver-green, mostly basal; proximalmost blades 3–4 × 1–1.5 cm, 1-pinnately lobed, lobes mostly 2–3 mm wide; blades of flowering stems somewhat reduced, (1–)2–3(–5) × 0.15 cm, mostly entire; apices rounded, faces densely hairy. |
Involucres | globose, 2–3 × 1.5–2.5 mm. |
broadly campanulate, 4–5(–7) × 2–3 mm. |
Florets | pistillate 0–2 (raylike, laminae to 1 mm); bisexual 1–3; corollas 1–1.5 mm (style branches of ray florets elongate, exsert, epapillate, tips acute; of disc florets, short, truncate, papillate). |
pistillate 8–10 (2–2.8 mm); functionally staminate 22–32; corollas pale yellow, 2.2–4.5 mm, glandular. |
Phyllaries | (8–15) ovate, canescent or tomentose. |
(ovate, margins broadly scarious) densely tomentose. |
Heads | (usually nodding) in arrays 6–25 × 1–4 cm (branches erect, somewhat curved). |
borne singly or (clustered in 2s and 3s on lateral branches; peduncles 0 or to 5 mm) in paniculiform arrays, (2–)4–9 × 1–1.5(–2) cm. |
Cypselae | (ellipsoid, 5-ribbed) 0.8–1 mm, glabrous. |
(light brown) ellipsoid, flattened (faintly nerved), 1.5–2 mm, sparsely hairy, glabrous or resinous. |
2n | = 18, 36, 72. |
|
Artemisia bigelovii |
Artemisia porteri |
|
Phenology | Flowering early summer–late fall. | Flowering mid–late summer. |
Habitat | Deserts, sandy or alkaline soils, rock outcrops | Barren clay and gravelly soils |
Elevation | 1000–2500 m (3300–8200 ft) | 1800–2000 m (5900–6600 ft) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT
|
MT; WY |
Discussion | Artemisia bigelovii of the southwestern deserts is easily confused in the field with A. tridentata, even though it is well distinguished ecologically and morphologically. Systematic placement within subg. Tridentatae remains problematic. Presence of “ray” florets (though rare) and vestigial spines on the pollen (R. P. Wodehouse 1935) suggest a relationship with groups ancestral to Tridentatae. The species also has the unusual characteristic of lignified trichomes (L. M. Shultz 1986b). Further research may help to determine proper placement; its affinities may be with members of subg. Artemisia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Although Cronquist observed that Artemisia porteri may be an autopolyploid derivative of A. pedatifida, morphologic similarities to northerly cespitose taxa suggest a more complex origin. Artemisia porteri is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 512. | FNA vol. 19, p. 509. |
Parent taxa | Asteraceae > tribe Anthemideae > Artemisia > subg. Tridentatae | Asteraceae > tribe Anthemideae > Artemisia > subg. Drancunculus |
Sibling taxa | ||
Synonyms | A. petrophila, Seriphidium bigelovii | |
Name authority | A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 4(5): 110. (1857) | Cronquist: Madroño 11: 145. (1951) |
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