By Doug Collicutt Manitoba's wildflower watching season starts each year with our floral emblem, the prairie crocus (Anemone patens) in late April. It ends in late September or early October when the last of the wild aster blossoms succumb to the frosty nights. From late August through September, and often well into October, asters dot our landscapes. Wherever you are in Manitoba, asters of one sort or another are the floral harbingers of autumn. We have about 20 species of asters in Manitoba, depending on which source you choose to use and what the taxonomists have been up to lately. () Asters of one species or another occur throughout the province and in nearly every type of habitat in our province, from wetlands and prairies to deciduous and coniferous forests. Most asters are small to medium sized plants (20-100 cm high) with leafy stems. They have numerous small flowers (usually <2 cm across) ranging from pure white to dark blue in colour. Taxonomists, people who study and determine the evolutionary relationships of living organisms, are renowned for, collectively, changing their minds. Revisions to plant and animal names and relationships - taking a species out of one grouping and putting it elsewhere, often renaming it in the process - often results in the numbers of species of this or the other group changing. Flower Structure Asters bloom late in the growing season, providing us with late-season flowers, but, more importantly, providing bees, butterflies and other insects with nectar and pollen as they prepare for winter. Asters flower late, but produce seeds rapidly. Each "flower" will produce a dandelion-like head of fluffy seeds. Seed head of a New England Aster (Aster novae-angliae) The seeds are tiny and are spread to the winds before the snow flies. If the seed comes to rest in favourable conditions it will germinate in the following spring. Most asters are good colonizers and will establish quickly in disturbed sites. Beware of establishing some types of asters in a garden setting. Species such as Smooth Aster (Aster laevis) and Many-Flowered Aster (Aster ericoides) are very aggressive and can take over large sections of your garden. More on gardening and landscaping with native plants in our Spring Issue! Origin of name: Aster = star (Latin and Greek) In both Latin and Greek, aster refers to star. Aster plants were named for the stars that they resemble in both shape and numbers, as opposed to sunflowers (Helianthus spp.) which have large, and less numerous, yellow, "sun-like" flowers. Beautiful Sunflower (Helianthus laetiflorus) Visited by a skipper. Some of the information for this article was drawn from: Budd's Flora of the Canadian Prairie Provinces, by J. Looman and K.F. Best Research Branch, Agriculture Canada Publication 1662, 1987.   Some books to help you identify Manitoba's asters or other wildflowers: Budd's Flora of the Canadian Prairie Provinces, by J. Looman and K.F. Best Research Branch, Agriculture Canada Publication 1662, 1987. The Peterson Field Guide Series, No. 17: A Field Guide to Wildflowers of Northeastern and Northcentral North America by R.T. Peterson and M. McKenny. 1968. Houghton Mifflin Co. A Guide to Field Identification: Wildflowers of North America, by F.D. Venning. 1984. Golden Press. Manitoba's Tall Grass Prairie: A Field Guide to an Endangered Space by Tom Reaume. Eco Series No. 3, Manitoba Naturalists Society. 1993.