''Symphyotrichum laeve'' (formerly ''Aster laevis'') is a

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

native to

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

, the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

, and

Coahuila Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

(

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

). It has the common names of smooth blue aster, smooth aster, smooth-leaved aster, glaucous Michaelmas-daisy and glaucous aster.

Description

Smooth aster is tall. Its leaves are arranged alternately on the stems, and their shape varies among

lanceolate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regula ...

, oblong-

ovate Ovate may refer to: * Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe A hand axe (or handaxe or Acheulean hand axe) is a prehistoric stone tool with two faces that is the longest-used ...

, oblong-

obovate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...

, and ovate. They measure from long and from wide. They are usually hairless, and the leaf edges are entire or bluntly or sharply toothed (

crenate A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

serrate Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied ...

), sometimes with smaller teeth ( serrulate). Symphyotrichum laeve 44271027.jpg Symphyotrichum laeve 50344044.jpg The

flower head A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

s are arranged in clusters (

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit In botany, a fruit is the seed-bearing structure in flowering plants that is ...

s). Each flower head has 13 to 23

ray floret The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

s with pale to dark blue or purple petals ( laminae), and 19 to 33

disc floret The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae we ...

s that start out yellow and eventually turn purplish-red. The whole flowerhead measures across. Symphyotrichum laeve 105736406.jpg Symphyotrichum laeve 145337525.jpg Symphyotrichum laeve 38098561.jpg The seeds are cypselae with

pappi In Asteraceae, the pappus is the modified calyx, the part of an individual floret, that surrounds the base of the corolla tube in flower. It functions as a wind-dispersal mechanism for the seeds. The term is sometimes used for similar s ...

(bristles at their tips). Like the hairs on dandelion seeds, the pappi allow the seeds to be spread by the wind. Symphyotrichum laeve 34324805.jpg

Taxonomy

There are four varieties: ''Symphyotrichum laeve'' var. ''laeve'', ''S. laeve'' var. ''geyeri'' (Geyer's aster), ''S. laeve'' var. ''concinnum'', and ''S. laeve'' var. ''purpuratum''. Hybrids with this species and others of the genus have been reported, including three named as follows: * ''Symphyotrichum'' × ''gravesii'' between ''S. laeve'' var. ''laeve'' and '' S. dumosum''; * ''Symphyotrichum'' × ''versicolor'' between ''S. laeve'' var. ''laeve'' and ''S. novi-belgii'' var. ''novi-belgii''; and, * ''Symphyotrichum'' × ''woldenii'' between ''S. laeve'' var. ''laeve'' and '' S. praealtum'', which instead may be between '' S. oolentangiense'' and ''S. praealtum''. Aster gravesii (Symphyotrichum x gravesii) specimen (cropped).jpg , ''Symphyotrichum'' × ''gravesii'' Symphyotrichum x versicolor specimen (cropped).jpg , ''Symphyotrichum'' × ''versicolor'' Aster woldenii isotype (inflorescence).jpg , ''Symphyotrichum'' × ''woldenii''

Distribution and habitat

''Symphyotrichum laeve'' varieties are native to

, the

, and

(

). The species is introduced in

Québec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirteen p ...

and

New Brunswick New Brunswick (french: Nouveau-Brunswick, , locally ) is one of the thirteen Provinces and territories of Canada, provinces and territories of Canada. It is one of the three Maritime Canada, Maritime provinces and one of the four Atlantic Canad ...

. ''S. laeve'' grows in fields, open woods, and along roadsides in rocky or dry soil and full sun.

Ecology

''Symphyotrichum laeve'' blooms in late summer and early fall. It is pollinated by many native bees and attracts butterflies. It is a larval host for the pearl crescent butterfly (''Phyciodes tharos'').

Citations

References

* * * * * * * * * *

External links

Astereae Lab - University of Waterloo

Ontario Wildflowers
{{Taxonbar, from1=Q544417, from2=Q21871635, from3=Q24691681, from4=Q24691678, from5=Q24691680, from6=Q24691682 laeve Flora of Canada Flora of the United States Plants used in traditional Native American medicine Plants described in 1753 Taxa named by Carl Linnaeus