Flora of North America species comparison

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Erigeron melanocephalus

Erigeron annuus

black-head fleabane

annual daisy, annual fleabane, eastern daisy fleabane, sweet scabrous fleabane, vergerette annuelle
Habit Perennials, 3–12(–21 at lower elevations) cm; fibrous-rooted, rhizomatous, caudices decumbent, often branched, rhizomelike, sometimes taprootlike. Annuals, (10–)60–150 cm; fibrous-rooted or taprooted.
Stems

erect, distally villous (hairs with black cross walls), minutely glandular near heads.

erect, sparsely piloso-hispid (hairs spreading), sometimes strigose distally, eglandular.
Leaves

mostly basal (persistent), some cauline;

blades spatulate to oblanceolate, (10–)20–50(–150) × 4–6(–15) mm, cauline linear, bractlike, margins entire (apices rounded to retuse), faces glabrous or sparsely hirsute, eglandular.

basal (usually withering by flowering) and cauline;

basal blades mostly lanceolate to oblanceolate or ovate, 15–80 × 3–20 mm, margins coarsely serrate to nearly entire, faces sparsely strigoso-hirsute, eglandular;

cauline lanceolate to oblong, little reduced proximal to midstem.
Involucres

6–9 × 10–14 mm.

3–5 × 6–12 mm.
Ray florets

45–74;

corollas white to purple, 7–11 mm (mostly 1–2 mm wide), laminae spreading, tardily coiling.

80–125;

corollas white, 4–10 mm, laminae tardily coiling.
Disc corollas

2.4–3.2 mm.

2–2.8 mm.
Phyllaries

in 2(–3) series, sparsely villoso-sericeous (hairs flattened, cross walls black, imparting distinct black color to involucres), glandular.

in 2–3(–4) series, sparsely villous or hirsuto-villous, minutely glandular.
Heads

1.

ca. 5–50+ in loosely paniculiform or corymbiform arrays.
Cypselae

(oblanceoloid-oblong) 2–2.3 mm, 2-nerved, faces strigoso-hirsute;

pappi: outer of setae, inner of 15–30 bristles.

0.8–1 mm, 2-nerved, faces sparsely strigose;

pappi: outer minute crowns of setae or narrow scales, inner 0 (rays) or of 8–11 bristles (disc).
2n

= 18.

= 27.

Erigeron melanocephalus

Erigeron annuus
Phenology Flowering Jul–Aug. Flowering Jun–Aug(–Nov).
Habitat Rocky slopes, talus, alpine and subalpine meadows, subalpine spruce-fir Mostly open, disturbed habitats, especially roadsides, fields, waste areas
Elevation 3100–4000 m (10200–13100 ft) 0–500(–2200) m (0–1600(–7200) ft)
Distribution
from FNA
CO; NM; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CA; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; BC; MB; NB; NF; NS; ON; PE; QC; SK; SPM; Mexico (Hidalgo); Central America (Costa Rica, Nicaragua, Panama); Europe; Asia
[WildflowerSearch map]
[BONAP county map]
Discussion

Erigeron annuus is apparently native to eastern North America (United States and southern Canada) and is introduced elsewhere; it probably occurs in North Dakota and Alberta; apparently it has not been documented there. Apparent intermediates between E. annuus and E. strigosus are encountered.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 20, p. 323. FNA vol. 20, p. 344.
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. 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. 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
Synonyms E. uniflorus var. melanocephalus Aster annuus, E. annuus var. discoideus
Name authority (A. Nelson) A. Nelson: Bull. Torrey Bot. Club 26: 246. (1899) (Linnaeus) Persoon: Syn. Pl. 2: 431. (1807)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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