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

Rydberg's fleabane

Zion fleabane

Habit Perennials, 2.5–6 cm; taprooted, caudex branches relatively short, thick. Perennials, 1.5–25 cm (becoming colonial); taprooted or fibrous-rooted, stoloniform branches persistent (1–3.5 cm), lignescent, bearing leaf tufts at tips, usually not retaining old leaf bases.
Stems

erect, finely hirsutulous to villosulous, eglandular.

erect to ascending or decumbent, glabrous proximally, strigose on distal 1/2, minutely glandular near heads.

Leaves

mostly basal (persistent);

blades linear-oblanceolate to narrowly spatulate, 10–50 × 1–3 mm, cauline mostly on proximal 1/2 of stems, reduced distally, margins entire (apices obtuse to rounded), abaxial faces glabrous, adaxial glabrous or sparsely villous, eglandular.

basal (persistent) and cauline;

basal blades oblanceolate to oblanceolate-spatulate, 50–760 × 1–11 mm, margins usually pinnately 3–5-lobed (sinuses reaching nearly to midveins), sometimes entire to dentate and mixed with lobed, faces glabrous or sparsely strigose, eglandular;

cauline blades linear, gradually reduced distally, margins entire.

Involucres

5–6 × 7–12 mm.

2–4.5 × 3.5–7 mm.

Ray florets

15–35;

corollas usually bluish to purplish, rarely white, 6–9 mm, laminae coiling.

22–38(–46);

corollas white, drying pink to lavender or blue, often with abaxial lilac midstripe, 4–7 mm, laminae not coiling or reflexing.

Disc corollas

3.7–5 mm.

1.6–2.8 mm (throats slightly indurate and inflated).

Phyllaries

in 2–3 series, densely and finely hirsuto-villous (hairs without colored cross walls), minutely and inconspicuously glandular.

in 3–5 series, moderately hirsute to hirtellous, minutely glandular.

Heads

1.

1–4.

Cypselae

1.8–2 mm, 2-nerved, faces sparsely strigose;

pappi: outer of setae, inner of 15–20 bristles.

1–1.5 mm, 2-nerved, faces sparsely strigose;

pappi: outer of setae, inner of 7–15(–19) (persistent) bristles.

Erigeron rydbergii

Erigeron sionis

Phenology Flowering Jun–Aug.
Habitat Open subalpine to alpine slopes
Elevation 2000–3200 m (6600–10500 ft)
Distribution
from FNA
ID; MT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

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

Key
1. Basal leaves usually with linear-oblanceolate lobes, less commonly entire to dentate, blades and/or lobes 1–3(–4) mm wide; ray corollas drying white to pink or light lavender; sandstone
var. sionis
1. Basal leaves entire or dentate, rarely deeply lobed, blades (2–)3–5(–11) mm wide; ray corollas drying pink to dark blue; limestone
var. trilobatus
Source FNA vol. 20, p. 293. FNA vol. 20, p. 343.
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. 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. 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. 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
Subordinate taxa
E. sionis var. sionis, E. sionis var. trilobatus
Name authority Cronquist: Brittonia 6: 191. (1947) Cronquist: Brittonia 6: 258. (1947)
Web links