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Big Horn fleabane

Engelmann's fleabane

Habit Perennials, 10–18 cm; taprooted, caudices multicipital or branched. Perennials, 3–20(–30) cm; taprooted, caudex branches relatively short and thick.
Stems

erect to ascending (branched, brittle), hispido-hirsute (hairs brittle), minutely glandular.

erect, loosely to closely, sparsely to moderately strigose (hairs 0.1–0.9 mm), usually minutely glandular (glands barely evident), sometimes eglandular.

Leaves

basal (often not persistent) and cauline;

blades spatulate 15–30 × 1.5–4 mm, cauline gradually reduced distally (reduced to bracts on peduncles), margins usually 3-lobed (lobes linear to oblong-oblanceolate, about as wide as central portion of blades), sometimes 2-ternate or (cauline) entire, faces sparsely hispido-hirsute, minutely glandular.

basal (usually persistent) and cauline (petioles prominently ciliate at least on proximal portions, hairs spreading, thick-based);

basal blades linear-oblanceolate, 20–100 × 1–4 mm, margins entire, faces strigose, eglandular;

cauline usually restricted to proximal 1/2 of stems, slightly reduced distally.

Involucres

4–5 × 6–9 mm.

3.5–5(–6) × 7–12 mm.

Ray florets

20–40;

corollas white to bluish, sometimes drying pink, 3–6 mm, laminae not coiling or reflexing.

(35–)45–100;

corollas white, sometimes pink or bluish, 5–10 mm, laminae (0.8–1.1 mm wide) primarily reflexing, sometimes also weakly coiling at the tips.

Disc corollas

2.5–3.5 mm.

(2.5–)2.7–4.2 mm (throats indurate and inflated, densely puberulent).

Phyllaries

in 2–3 series, glabrous or sometimes sparsely hispid, densely minutely glandular.

in 2–3(–4) series, coarsely hirsuto-villous, sparsely to moderately minutely glandular.

Heads

usually 2–4.

1(–3).

Cypselae

2–2.3 mm, 2-nerved, faces sparsely strigose;

pappi: outer of setae, inner of 12–20 bristles.

1.4–1.8 mm (oblong), 2-nerved, faces sparsely strigose;

pappi: outer usually of narrow scales, sometimes 0 or of setae, inner of 12–20 bristles.

Erigeron allocotus

Erigeron engelmannii

Phenology Flowering May–Aug. Flowering (Apr–)May–Jul.
Habitat Dry, calcareous sites on cliff faces, ledges, talus slopes, ridgetops, rock outcrops, barren redbeds, sometimes with Utah juniper, mountain mahogany, or sagebrush Dry, sandy or rocky sites, prairies, often with sagebrush, rabbitbrush, juniper, pinyon-juniper, salt desert shrub
Elevation 1300–2300 m (4300–7500 ft) 1300–2500 m (4300–8200 ft)
Distribution
from FNA
MT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; ID; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

The brittle, hispid vestiture, and multiple small heads (more than one per stem) with short rays of Erigeron allocotus are unusual among its putative relatives with 3-parted leaves.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Plants from Chaffee and Fremont counties, Colorado, have strigose leaves and the compact habit of Erigeron engelmannii but sparsely spreading-hirsute stems; they may be intermediate between E. engelmannii and E. concinnus. Unusual variation in the pappi of E. engelmannii also suggests that the species needs study and better definition.

A. Cronquist observed that “Erigeron engelmannii intergrades completely with E. pumilus, yet has two geographic subspecies of its own, and shows no distributional similarity to the [taxa] of E. pumilus,” and that E. engelmannii is “smaller and more delicate, with shorter finer hairs, and [has] smaller heads with usually fewer ligules.”

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 20, p. 299. FNA vol. 20, p. 290.
Parent taxa Asteraceae > tribe Astereae > Erigeron Asteraceae > tribe Astereae > Erigeron
Sibling taxa
E. abajoensis, E. acomanus, E. acris, E. aequifolius, E. algidus, E. aliceae, E. alpiniformis, E. anchana, E. annuus, E. aphanactis, E. arenarioides, E. argentatus, E. arisolius, E. arizonicus, E. asperugineus, E. aureus, E. barbellulatus, E. basalticus, E. bellidiastrum, E. bigelovii, E. biolettii, E. blochmaniae, E. bloomeri, E. breweri, E. caespitosus, E. calvus, E. canaani, E. canus, E. cascadensis, E. cavernensis, E. cervinus, E. chrysopsidis, E. clokeyi, E. compactus, E. compositus, E. concinnus, E. consimilis, E. corymbosus, E. coulteri, E. cronquistii, E. davisii, E. decumbens, E. denalii, E. disparipilus, E. divergens, E. eatonii, E. elatior, E. elatus, E. elegantulus, E. elmeri, E. engelmannii, E. evermannii, E. eximius, E. filifolius, E. flabellifolius, E. flagellaris, E. flettii, E. foliosus, E. formosissimus, E. garrettii, E. geiseri, E. glabellus, E. glacialis, E. glaucus, E. goodrichii, E. gracilis, E. grandiflorus, E. greenei, E. heliographis, E. hessii, E. howellii, E. humilis, E. hyperboreus, E. hyssopifolius, E. inornatus, E. jonesii, E. kachinensis, E. karvinskianus, E. klamathensis, E. kuschei, E. lackschewitzii, E. lanatus, E. lassenianus, E. latus, E. leibergii, E. leiomerus, E. lemmonii, E. linearis, E. lobatus, E. lonchophyllus, E. maguirei, E. mancus, E. maniopotamicus, E. mariposanus, E. melanocephalus, E. miser, E. modestus, E. muirii, E. multiceps, E. nanus, E. nauseosus, E. nematophyllus, E. neomexicanus, E. nivalis, E. ochroleucus, E. oreganus, E. oreophilus, E. ovinus, E. oxyphyllus, E. pallens, E. parishii, E. parryi, E. peregrinus, E. petrophilus, E. philadelphicus, E. pinnatisectus, E. piperianus, E. piscaticus, E. poliospermus, E. porsildii, E. pringlei, E. procumbens, E. pulchellus, E. pulcherrimus, E. pumilus, E. purpuratus, E. pygmaeus, E. quercifolius, E. radicatus, E. reductus, E. religiosus, E. rhizomatus, E. robustior, E. rybius, E. rydbergii, E. salishii, E. salmonensis, E. sanctarum, E. saxatilis, E. sceptrifer, E. scopulinus, E. serpentinus, E. sionis, E. sivinskii, E. sparsifolius, E. speciosus, E. strigosus, E. subglaber, E. subtrinervis, E. supplex, E. tenellus, E. tener, E. tenuis, E. tracyi, E. trifidus, E. tweedyi, E. uintahensis, E. uncialis, E. uniflorus, E. untermannii, E. ursinus, E. utahensis, E. vagus, E. velutipes, E. vernus, E. versicolor, E. vetensis, E. vicinus, E. vreelandii, E. watsonii, E. wilkenii, E. yukonensis
E. abajoensis, E. acomanus, E. acris, E. aequifolius, E. algidus, E. aliceae, E. allocotus, E. alpiniformis, E. anchana, E. annuus, E. aphanactis, E. arenarioides, E. argentatus, E. arisolius, E. arizonicus, E. asperugineus, E. aureus, E. barbellulatus, E. basalticus, E. bellidiastrum, E. bigelovii, E. biolettii, E. blochmaniae, E. bloomeri, E. breweri, E. caespitosus, E. calvus, E. canaani, E. canus, E. cascadensis, E. cavernensis, E. cervinus, E. chrysopsidis, E. clokeyi, E. compactus, E. compositus, E. concinnus, E. consimilis, E. corymbosus, E. coulteri, E. cronquistii, E. davisii, E. decumbens, E. denalii, E. disparipilus, E. divergens, E. eatonii, E. elatior, E. elatus, E. elegantulus, E. elmeri, E. evermannii, E. eximius, E. filifolius, E. flabellifolius, E. flagellaris, E. flettii, E. foliosus, E. formosissimus, E. garrettii, E. geiseri, E. glabellus, E. glacialis, E. glaucus, E. goodrichii, E. gracilis, E. grandiflorus, E. greenei, E. heliographis, E. hessii, E. howellii, E. humilis, E. hyperboreus, E. hyssopifolius, E. inornatus, E. jonesii, E. kachinensis, E. karvinskianus, E. klamathensis, E. kuschei, E. lackschewitzii, E. lanatus, E. lassenianus, E. latus, E. leibergii, E. leiomerus, E. lemmonii, E. linearis, E. lobatus, E. lonchophyllus, E. maguirei, E. mancus, E. maniopotamicus, E. mariposanus, E. melanocephalus, E. miser, E. modestus, E. muirii, E. multiceps, E. nanus, E. nauseosus, E. nematophyllus, E. neomexicanus, E. nivalis, E. ochroleucus, E. oreganus, E. oreophilus, E. ovinus, E. oxyphyllus, E. pallens, E. parishii, E. parryi, E. peregrinus, E. petrophilus, E. philadelphicus, E. pinnatisectus, E. piperianus, E. piscaticus, E. poliospermus, E. porsildii, E. pringlei, E. procumbens, E. pulchellus, E. pulcherrimus, E. pumilus, E. purpuratus, E. pygmaeus, E. quercifolius, E. radicatus, E. reductus, E. religiosus, E. rhizomatus, E. robustior, E. rybius, E. rydbergii, E. salishii, E. salmonensis, E. sanctarum, E. saxatilis, E. sceptrifer, E. scopulinus, E. serpentinus, E. sionis, E. sivinskii, E. sparsifolius, E. speciosus, E. strigosus, E. subglaber, E. subtrinervis, E. supplex, E. tenellus, E. tener, E. tenuis, E. tracyi, E. trifidus, E. tweedyi, E. uintahensis, E. uncialis, E. uniflorus, E. untermannii, E. ursinus, E. utahensis, E. vagus, E. velutipes, E. vernus, E. versicolor, E. vetensis, E. vicinus, E. vreelandii, E. watsonii, E. wilkenii, E. yukonensis
Name authority S. F. Blake: J. Wash. Acad. Sci. 27: 379. (1937) A. Nelson: Bull. Torrey Bot. Club 26: 247. (1899)
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