Individuals in the spring, with basal rosettes, often have leaf shapes quite different from those with cauline leaves seen later in the season.

Individuals may vary considerably in plant size and array development depending upon growing conditions.

Disc florets are yellow to white, becoming pinkish, reddish purple, or brown when mature.

Nees emphasized the uniqueness of this plant in having its pappus hairs arranged in a coherent, basal ring.

[4] This structure is the basis for the scientific name of this genus, which derives from Ancient Greek σύμφυσις (sýmphysis) "growing together" and θρίξ (thríks; stem τριχ- trich-) "hair".

Regardless, according to the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN), the timing of the genus' establishment gives it precedence over other names.

[7][11] As of June 2021[update], Catalogue of Life listed 106 accepted species and identified naturally-occurring hybrids, including the following:[12] Ray florets in the Symphyotrichum genus are exclusively female, each having a pistil (with style, stigma, and ovary) but no stamen.

[a] The ovary has an attached style that extends outward from between the ray floret corolla and the rest of the flower head.

The disk floret's stigma stays closed while pollen is on it, keeping its ovary safe from self-pollination.