Canadanthus

G. L. Nesom

Phytologia 77: 250. 1995.

Common names: Aster
Etymology: Canada and Greek anthos, flower, alluding to mainly Canadian distribution
Synonyms: Aster subg. Canadanthus (G. L. Nesom) Semple
Treatment appears in FNA Volume 20. Treatment on page 458. Mentioned on page 18, 459, 466.
 TaxonIllustrator 
FNA20 P50 Canadanthus modestus.jpegCanadanthus modestus
Ampelaster carolinianus
Almutaster pauciflorus
Yevonn Wilson-Ramsey
Marjorie C. Leggitt
Yevonn Wilson-Ramsey

Perennials, 30–100 (–130) cm (rhizomatous). Stems ascending to erect, simple, ± densely villous, stipitate-glandular distally. Leaves cauline; alternate; sessile; blades 1-nerved, elliptic-lanceolate or oblanceolate to (sometimes narrowly) oblanceolate or lanceolate, margins entire to serrate, abaxial faces glabrate to ± strigose, adaxial sparsely villous, (distal) stipitate-glandular. Heads radiate, usually in leafy, irregularly flat-topped, paniculiform to corymbiform arrays, sometimes borne singly. Involucres cylindro-campanulate, {(5–) 7–10 ×} 12–16 mm. Phyllaries 26–60+ in 3–5 series, 1-nerved (flat), lanceolate, subequal, outer ± foliaceous, inner herbaceous, bases not indurate, abaxial faces stipitate-glandular. Receptacles flat, pitted, epaleate. Ray-florets 20–65 in 1 series, pistillate, fertile; corollas pale to dark purple or rose (coiling). Disc-florets 40–65, bisexual, fertile; corollas whitish to pale-yellow, turning purple, lobes sometimes purplish-tinged, ± ampliate, tubes shorter than tubular throats, lobes 5, erect, triangular; style-branch appendages narrowly triangular (hairy). Cypselae obconic-fusiform, compressed, 4–9-nerved, faces sparsely strigose, eglandular; pappi of 20–35+ cinnamon, equal, barbellate, attenuate bristles in 1 series. x = 9.

Distribution

North America

Discussion

Species 1.

G. L. Nesom (1994b, 2000) established Canadanthus as a monotypic genus and provided justification at the morphologic and cytologic levels. According to Nesom, Canadanthus (x = 9) belongs in Symphyotrichinae, in an isolated position similar to that of Ampelaster (x = 9), Almutaster (x = 9), and Psilactis (x = 9, 5, 4); most of the species of the subtribe are in genus Symphyotrichum (x = 8, 7, 5, 4). J. C. Semple and L. Brouillet (1980) had placed Canadanthus in Aster subg. Modesti. A molecular phylogenetic study of North American asters based on restriction site analysis of chloroplast DNA by Xiang C. and Semple (1996) showed Canadanthus to be basal to Ampelaster and Symphyotrichum. The basal position of Canadanthus in subtribe Symphyotrichinae was confirmed in a phylogeny of North American and Eurasian asters using nuclear ribosomal DNA (ITS) (Semple et al. 2002). Canadanthus modestus has been associated also with Eurybia sibirica, notably by Á. Löve and D. Löve (1982b) when they created the genus Weberaster, or with E. radulina (e.g., A. G. Jones 1980; Jones and D. A. Young 1983). This may be due to similarities in the habit, foliage, and involucres of these species.

Selected References

None.

... more about "Canadanthus"
stipitate-glandular +, glabrate +  and more or less strigose +
stipitate-glandular +  and villous +
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
flat-topped +
Luc Brouillet +
G. L. Nesom +
decurrent +
not indurate +
oblanceolate;oblanceolate or lanceolate +
rugulose +  and muricate +
not 2-lipped +  and actinomorphic +
purplish-tinged +, whitish +  and pale-yellow +
ampliate +
beaked +, 2-ribbed +  and 5-ribbed +
compressed +  and obconic-fusiform +
fertile +  and bisexual +
fertile +  and bisexual +
North America +
Canada and Greek anthos, flower, alluding to mainly Canadian distribution +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
cylindro-campanulate +
1.2 cm12 mm <br />0.012 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
triangular +
entire +  and serrate +
2-carpellate +
lanceolate +
bearing subulate enations +, hairy +  and bristly +
concave;usually flat;conic +
exalbuminous +
ascending +  and erect +
appendaged +  and truncate +
papillate +  and smooth +
Aster subg. Canadanthus +
Canadanthus +
Asteraceae tribe Astereae +
100 cm1,000 mm <br />1 m <br /> (130 cm1,300 mm <br />1.3 m <br />) +
30 cm300 mm <br />0.3 m <br /> (100 cm1,000 mm <br />1 m <br />) +
tree +, shrub +  and subshrub +