Generic delimitation in Astereae has long been a source of disagreement among botanists. The ways in which they treat the large and diverse genus Aster usually reflect their philosophy on generic concepts, and although there are many variations, in general there have historically been two schools of thought. The first approach maintains a very inclusive generic concept of a large genus Aster, with subdivision of the genus into several subgenera. The second approach was to segregate many distinctive small genera from Aster, thus adopting a narrow generic concept As a result of new in-depth studies of phenotype features and, more recently, DNA sequences, combined with reasonably strict adherence to the tenets of phylogenetic systematics, the genus Aster is now much more narrowly and more naturally defined than before. Consequently many of the species, including this one, that were formerly accepted in a looser definition of that genus have now been transferred to several more narrowly defined genera.
Aster cordifolius L.
Aster finkii moratus Shinners
Aster leiophyllus Porter
Aster lowrieanus Porter
Aster sagittifolius Wedem. ex Willd.
Symphyotrichum lowrieanum (Porter) G.L.Nesom
Symphyotrichum sagittifolium (Wedem. ex Willd.) G.L.Nesom
Common Name: Common Blue Wood Aster
Symphyotrichum cordifolium is a herbaceous perennial plant with a more or less woody, rhizomatous rootstock. It produces clusters of 1 - 5 or more erect stems 20 - 120cm tall[
Much grown as an ornamental, there are many named varieties. The plant is also sometimes harvested as a food and a medicine.
Eastern N. America - Nova Scotia and New Brunswick to Ontario, Minnesota, Georgia and Missouri.
Rich, mostly mesic, rocky to loamy soils, open wooded slopes and bluffs, stream banks, moist ledges, swampy woods, border of beech-maple or oak-hickory forets, clearings, thickets, roadsides[
|Pollinators||Bees, Flies, Beetles, Lepidoptera, Self
|Cultivation Status||Ornamental, Wild
Symphyotrichum cordifolium is a plant mainly of the temperate zone, moving into the subtropics in the south of its range. It is found at elevations up to 1,000 metres. It grows best in areas where annual daytime temperatures are within the range 12 - 24°c, but can tolerate 10 - 32°c[
]. When dormant, the plant can survive temperatures down to about -35°c, but young growth can be severely damaged at 0°c[
]. It prefers a mean annual rainfall in the range 600 - 1,200mm, but tolerates 500 - 1,500mm[
Succeeds in most good garden soils[
], preferring one that is well-drained and moisture retentive[
]. Prefers a sunny position[
]. Prefers a rich soil[
]. Prefers a pH in the range 5.7 - 7.5, tolerating 5.5 - 8[
Pinching back the shoot tips several times before mid-July will help control plant height, promote bushiness and perhaps obviate the need for staking[
Plants often self-sow when growing in a suitable position[
]. If self-sowing is a problem, then cut the stems back to grounf level soon after flowering and before the seed is formed[
]. They can be naturalized in a woodland or other wild garden[
The flowers are very attractive to butterflies[
Most species in this genus seem to be immune to the predations of rabbits[
Hybridizes freely with other members of this genus[
Leaves - cooked and used as greens[
An infusion of the plant is used as an aromatic nervine and also in the treatment of rheumatism[
The roots are used in the treatment of hysteria, nervous irritability, painful menstruation, rheumatism, and similar difficulties[
Seed - surface sow in spring in a cold frame. Do not allow the compost to become dry. Pre-chilling the seed for two weeks can improve germination rates[
]. The seed usually germinates in 2 weeks at 20°c[
]. When large enough to handle, prick the seedlings out into individual pots and plant them out in the summer.
Division in spring or autumn[
Basal cuttings in late spring. Harvest the shoots when they are about 10 - 15cm long with plenty of underground stem. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.