The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

three-vein fleabane, threenerve fleabane

tuft daisy, tuft fleabane

Habit Perennials, 15–90 cm; rhizomatous to subrhizomatous, fibrous-rooted, caudices usually branched, woody, thick. Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched.
Stems

erect, moderately to densely hirsute (hairs 0.5–0.8 mm), eglandular.

decumbent-ascending (greenish proximally), usually densely hirsute to hirtellous (hairs spreading to deflexed, gradually attenuate, basal cells erect), sometimes strigose (in Saskatchewan and Yukon), eglandular.

Leaves

basal (usually withering by flowering) and cauline;

basal blades oblanceolate-spatulate, 30–80 × 6–20(–27) mm, margins entire, faces evenly hirsute to strigoso-hirsute, usually eglandular;

cauline blades lanceolate to oblong, oblong-ovate, or broadly ovate, nearly even-sized distally or sometimes mid largest (continuing to immediately proximal to heads, bases clasping to subclasping).

basal (persistent) and cauline;

basal blades (1–)3-nerved, narrowly oblanceolate to spatulate, (10–)20–90(–120) × 2–15 mm, margins entire (apices rounded to obtuse), faces densely hirtellous, eglandular;

cauline blades oblong-ovate to linear, ± reduced distally.

Involucres

6–9 × 13–20 mm.

4–7 × 9–18 mm.

Ray florets

100–150;

corollas blue to lavender, 7–18 mm (ca. 1 mm wide), laminae coiling at tips.

30–100;

corollas white to bluish, 5–15 mm, laminae coiling.

Disc corollas

4–5 mm.

3–4.4 mm.

Phyllaries

in 2–3(–4) series, moderately to densely hirsute, minutely glandular.

in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular.

Heads

1–6(–21) in corymbiform arrays.

1–4 (branches from distal 1/2 of stem).

Cypselae

1.6–2 mm, 2(–4)-nerved, faces sparsely strigose;

pappi: outer of setae, inner of 20–30 bristles.

1.7–2.2 mm, 2-nerved, faces sparsely strigose;

pappi: outer of setae or scales, inner of 15–25 bristles.

2n

= 18, 36.

Erigeron subtrinervis

Erigeron caespitosus

Phenology Flowering (Jun–)Jul–Sep. Flowering Jun–Aug.
Habitat Opening and margins, roadsides, often shaded, ponderosa pine, pine-fir, mixed conifer, aspen Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward
Elevation 1800–3000(–3500) m (5900–9800(–11500) ft) 1300–3000(–3600) m (4300–9800(–11800) ft)
Distribution
from FNA
CO; ID; MT; ND; NE; NM; SD; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

Erigeron subtrinervis is variable in vestiture, perhaps reflecting gene exchange with E. speciosus. Erigeron speciosus var. mollis (A. Gray) S. L. Welsh may be a recurrent hybrid; it is identified here within E. subtrinervis.

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

Erigeron caespitosus as recognized here is highly variable and perhaps justifiably could be divided into more than one taxon. Plants at lower elevations tend to produce tall stems branching above the middle and long, white rays. At higher elevations, especially in Idaho, western Montana, Utah, and Wyoming, stems tend to be shorter and simple and the rays commonly are blue to violet. In the Bitterroot Mountains (Ravalli and Deerlodge counties, Montana), short-stemmed, blue-rayed plants also have strigose cauline vestiture (in contrast to typically deflexed-hirtellous stems); these vestiture variants occur in the same area with plants apparently similar in all other features. Strigose populational variants also occur in Saskatchewan and Yukon, and E. abajoensis, largely distinguished by strigose cauline vestiture, might be considered a regional variant of E. caespitosus. In eastern Idaho and southwestern Montana, plants of E. caespitosus are commonly encountered with cauline leaves obovate and distinctly subclasping. Plants with strongly 3-nerved basal leaves occur in Carbon and Gallatin counties, Montana.

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

Source FNA vol. 20, p. 330. FNA vol. 20, p. 283.
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. 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. 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. 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. 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
Synonyms E. glabellus var. mollis, E. speciosus var. mollis
Name authority Rydberg ex Porter & Britton: Mem. Torrey Bot. Club 5: 328. (1894) Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840)
Web links