Questions and Answers
|Why use scientific names for the species?|
|How were genus and species names determined?|
|What happened to the genus "Aster"?|
|Why is scientific (Latin) terminology used here?|
|How were the photographs made?|
|How were the species descriptions developed?|
|What is the logic behind the dichotomous keys?|
|How were geographic distributions determined?|
|What about the ethics of collecting specimens?|
|May I make copies of these pages to take to the field?|
|How do I CONTACT the webmaster?|
Why use scientific names for the species? It has long been considered more accurate to identify an aster or a goldenrod by its scientific name, rather than its common name. For example, Tall Goldenrod (Solidago altissima) and Late Goldenrod (Solidago gigantea) both tend to be "tall", so why is one referred to as "tall"? By the same token, Late Goldenrod actually blooms earlier in New England than Tall Goldenrod - and for that matter, earlier than several of the other goldenrods as well. For your convenience, on the description pages for each of the species you will find some of the more often used common names for that species. In addition, please refer to the Aster and Goldenrod name cross-reference charts under the Resources section of this site for listings of the species' common names and their corresponding scientific names.
Return to Top
What happened to the genus "Aster"? There has never been complete agreement among scientists about the scientific names for aster and goldenrod species. "Synonyms" created over the decades by scores of botanists abound for many of the species. Thanks to recent advances in genetic research, scientists are now able to classify species more accurately. Consequently, the technical names for many of the asters and goldenrods, which we had learned over the years (with some difficulty), have of late been changed.
This is particularly true of the asters of New England, which have been completely renamed. The convenient and elegant genus name "Aster" has been replaced by a set of generally unfamiliar and sometimes hard to pronounce and spell names such, as "Symphyotrichum", "Ionactis" and "Doellingeria".
The decision to reclassify the North American aster species was not made on a whim. An enormous amount of careful research over several decades was invested into the current classification. The research revealed that the genus Aster, strictly-speaking, is primarily an "Old World" species. Aster, and its closest relatives are found mostly in Europe and Asia. The North American native "asters" (colloquially-speaking) are not morphologically and/or genetically close enough to Aster to be included within that genus. The "new" generic names we have in North America have actually been in existence for hundreds of years, though they were unused during much of that time. I suggest you read the Nesom (1994) article cited in the references page of this website. It is lengthy and very technical, but it covers a lot of ground and explains the grounding for the current classification.
We will use the new names to identify the aster species because they are more accurate. Besides, the new names aid in identifying the species by grouping like species together. That is, it is to our advantage to learn the new names!! The large, monolithic genus "Aster" has been divided into numerous, more cohesive genera. For example, "Eurybias" tend to share more in common with each other than with the other "aster" species. It makes very little sense to include a plant such as Ionactis linariifolius together with a plant such as Symphyotrichum cordifolium in the same genus.
Return to Top
Why is scientific (Latin) terminology used here? In most instances technical (i.e., scientific/Latin) terms will be used to describe the species, rather than common or vernacular terms. The reasons are . . . .
(1) Technical terms are usually more precise than their vernacular equivalents, and they are also more concise. For example, the term "serrate" means "having forward-pointing teeth along the margins or edges". It would become impossibly tedious to use these nine English words to refer to that leaf characteristic every time it was necessary.
(2) Moreover, if one desires to become proficient in the identification of these species, it will be necessary to go beyond the materials provided here and refer to detailed technical references, which exclusively use scientific terminology. The terminology is indeed daunting, and the professional references won't pamper you. What you will learn here will also help with your other botanical studies. One of the primary purposes of this website is educational, and the interactive, Illustrated Glossary provided here should assist you in using the advanced texts.
Nevertheless, some vernacular terms are used here. In some cases, especially when a vernacular term is short and unambiguous in meaning, that will be used. For example, it would be possible to refer to "stem leaves" as "cauline leaves". However, the word "stem" is reasonably clear and concise. Similarly, I usually use "upper" and "lower" with reference to locations along a stem, instead of "distal" and "proximal".
Each professional reference uses a mix of technical and vernacular terms, at the discretion of the authors, and they're not always consistent with each other. For instance, the Flora of North America, uses "glabrescent" to mean "slightly or sparsely hairy", whereas Semple and colleagues use the synonymous term "glabrate". Similarly, Semple and colleagues use the terms "capitula" and "capitulescence", whereas the Flora of North America use the more vernacular terms "heads" and "arrays".
I learned asters and goldenrods from reading Semple's books, so I tend to employ his terminology. I could live with "heads", but "arrays" doesn't describe the complex structures of these species as clearly as "capitulescence" does. "Array" is too vague. So, because I use "capitulescence" I feel it is necessary to use "capitula".
Regarding types of hairs, I have tried to keep the number of different terms to a minimum. Many people are already familiar with the terms "pubescent" and "glabrous". The former is a kind of catch-all term to describe "having hairs". I don't wish to swamp you with terminology needlessly. Here are a few of the terms used by botanists to describe various types of hairness - just a few of the ones that come to mind: pubescent, puberulent, scabrous, scaberulent, scaberulous, hirsute, hirsutulous, hirtellous, villous, villosulous, hispid, hispidulous, sericeous, pilose, pilosulous, strigose, stigillose. You get the point. The ones I tend to use are underlined. I don't expect anyone who's deep within a dark forest keying out species with only a hand lens to discern whether the hairs s/he sees are hirsute or minutely-hirsute (hirsutulous). "Pubescent" will do. :)
Return to Top
How were the species descriptions developed?
In general, descriptions provided in this guide are based primarily on field work, using live specimens. Detailed notes were made of those specimens. I also relied heavily on detailed photography, some of which is presented here. If questions remained, I consulted one or more of the professional references sited in the Bibliography.
Blooming periods (phenology) indicated on the species pages are approximate times when the majority of plants of a given species are in bloom. It isn't possible to provide exact time ranges due to a variety of factors. Climatic variations (temperatures, rainfall amounts) occur from year to year. Geographic locations are another major factor. Blooming times for southern New England may vary slightly from those in the northern part of the region. Similarly, times may vary between plants located on south-facing slopes and plants located on the north side of mountains.
There are always factors that lead to the presence of "early bloomers" or "stragglers" due to unique conditions, such as roadside or field mowing. Plants that were mowed earlier in the season may bloom much later than the rest of their species. One needs to exercise caution when stating that plants subjected to mowing are "in flower", if the date is significantly later than that of the majority of plants of the same species.
My records of field observations indicate the blooming stages for observed plants: early bud, late bud, in flower, immature fruit or fruit. To be considered "in flower" a plant had to have fully-opened capitula. I also used photographic records to determine blooming periods.
Height ranges listed for the species described here are the "typical" heights one will find in a majority of plants of a given species. For example, one can usually expect to find specimens of Symphyotrichum lanceolatum to vary in height between 3 and 6 feet. Of course, shorter or taller plants occur as well, but they are relatively uncommon. I once found a specimen of Solidago rugosa that was 8 feet tall, much taller than the typical 4 to 5 feet that members of this species attain. But such a tall plant is quite uncommon. In sum, I listed height ranges that we would normally expect to find in the field - not the rare extremes that sometimes occur.
Return to Top
What about the ethics of collecting specimens? Most of the species described here are common, locally common or extremely common - even ubiquitous. Thus, in most cases the ethics of collecting wild plants were not of concern. Whenever possible, specimens were returned to their original locations or to similar habitats after being photographed.
No species that is rare or protected by law in the state in which it was found was collected for photography. In those instances, photography was performed in field locations, even if it meant sacrificing image clarity or quality. The primary limitation in these cases was the ability to create extreme closeups of stem, leaf or flower parts due to the wind or light conditions during hours when photography had to be performed.
Return to Top
Return to Top
How were genus and species names determined? Every effort was made to use the latest scientific names "generally accepted" in the discipline. Where lack of consensus regarding genus or species names occurred, the names used by Flora of North America, Vol. 20 and/or the NatureServe website were adopted. Flora of North America now has a website.
Return to Top
What is the logic behind the dichotomous keys? The two keys were designed to allow you to identify these species in the field with only a hand lens. That is, you shouldn't have to take specimens back to a laboratory to be examined under a microscope. Thus, characteristics of leaves, stems, phyllaries and rays were used to distinguish the species, as much as possible.
Return to Top
Return to Site Home Page
May I make copies of these pages to take to the field? Yes, you may make copies for study at home or in the field. However, as these materials are copyrighted, you may not sell, reproduce for other people's use or distribute them in any way with prior permission of Arieh Tal.
Return to Top