Basionym Symphyotrichum pilosum (formerly Aster pilosus) is a perennial, herbaceous, flowering plant in the Asteraceae family native to central and eastern North America.

[7] The roots of S. pilosum have bulky and branched caudices that sometimes have long rhizomes[5] which store nutrients for the next year's flowering.

They are oblanceolate or obovate to spatulate with obtuse to rounded tips, and their bases are attenuate.

They grow in a rosette and develop prior to flowering, then wither or die during plant growth.

[5] Distal leaves, higher on the stem and on the branches with the flower heads, are lance-oblong, linear-lanceolate, linear, linear-oblanceolate, or linear-subulate.

The leaves get progressively smaller near the inflorescences; closest to the flower heads, their sizes are abruptly reduced.

[5] Flower heads of all members of the Asteraceae family have phyllaries which are small, specialized leaves that look like scales.

pilosum have small and sparse hairs, meaning they are hirsutulous, and those of variety pringlei are glabrous.

The phyllaries are appressed or slightly spreading, and the outer ones are oblong-lanceolate in shape, while the inner are linear.

Their margins appear white or light green, but they are actually translucent and may appear nibbled or worn away (in botanical terms, they are scarious and erose).

[10] The disks have 17 to 39[e] florets that start out as yellow and after opening, turn reddish purple or brown after pollination.

They are dispersed by the fall and winter winds and germinate when temperatures become warm in the spring.

[14] The specific epithet, second part of the scientific name, pilosum is from Latin pilosus meaning "with long soft hairs".

[7] As of November 2022[update], the holotype of Symphyotrichum pilosum, as Aster pilosus, was stored at the Herbarium Berolinense, Berlin Botanical Garden and Botanical Museum, Germany,[18] and the Symphyotrichum pilosum var.

pringlei, holotype was stored at the United States National Herbarium, National Museum of Natural History, Smithsonian Institution, Washington, D.C.[19] Images of both specimen sheets are shown in this section and were available at that time for more detailed viewing at the virtual online collection websites of their respective herbaria.

Two commonalities among the five species are their revolute phyllaries and their summer- and fall-forming basal leaf rosettes.

[12] S. chapmanii S. divaricatum S. glabrifolium S. graminifolium S. martii S. parviflorum S. patagonicum S. peteroanum S. potosinum S. regnellii S. subulatum S. tenuifolium S. vahlii S. ericoides S. falcatum S. adnatum S. walteri S. georgianum S. patens S. phlogifolium S. bimater S. chihuahuense S. hintonii S. moranense S. purpurascens S. trilineatum S. turneri S. campestre S. estesii S. fendleri S. fontinale S. grandiflorum S. oblongifolium S. pygmaeum S. yukonense S. novae-angliae S. concolor S. lucayanum S. plumosum S. pratense S. sericeum S. ascendens S. defoliatum S. ciliatum S. frondosum S. laurentianum S. chilense S. eatonii S. foliaceum S. greatae S. hallii S. hendersonii S. jessicae S. lentum S. molle S. spathulatum S. subspicatum S. turbinellum S. boreale S. bullatum S. burgessii S. carnerosanum S. dumosum S. eulae S. lanceolatum S. lateriflorum S. leone S. nahanniense S. ontarionis S. praealtum S. racemosum S. schaffneri S. simmondsii S. tradescantii S. welshii S. laeve S. oolentangiense S. anomalum S. ciliolatum S. cordifolium S. drummondii S. shortii S. undulatum S. urophyllum S. depauperatum S. kentuckiense S. parviceps S. pilosum S. porteri S. elliottii S. firmum S. prenanthoides S. puniceum S. rhiannon S. anticostense S. novi-belgii S. retroflexum S. robynsianum Two varieties are accepted by Plants of the World Online (POWO).

[21] Additionally, it has been determined that pollination has occurred between the two varieties or between the tetraploid and hexaploid cytotypes of S. p. var.

According to Flora of North America (FNA), it is native from west starting in Minnesota, then east to Maine, including Ontario and Québec; south along the Atlantic Seaboard including most southern and eastern states; the entire Midwest; the states bordering the Mississippi River except Louisiana; then with a northwest border to Arkansas; and, four Great Plains states, from south to north, Oklahoma, Kansas, Nebraska, and South Dakota.

States on the Atlantic Seaboard with no reported presence are Connecticut, Delaware, Maryland, Rhode Island, and Vermont, plus West Virginia.

FNA reports that it has been introduced to the Canadian provinces of British Columbia, New Brunswick, and Nova Scotia.

[4][25] NatureServe differs and includes a presence for this variety in Arkansas, Georgia, South Carolina, and Tennessee.

pilosum was reported by NatureServe as an introduced species in the Canadian provinces of British Columbia, New Brunswick, Nova Scotia, and Prince Edward Island;[24] and, by POWO in the countries of Belgium, France, Germany, Great Britain, India, Italy, Korea, Netherlands, and Spain.

It occurs less frequently[28] in natural prairies, open deciduous woods,[3] limestone outcrops,[29] and, very uncommonly, wetlands.

pringlei is common in calcium-rich ecosystems such as calcareous grasslands and fens,[7] limestone alvars,[31] shale outcrops,[28] and marly pannes.

[f][7] It also has been found in various partially-sandy or sandy areas,[28] on moraine cliffs along lakes in woodland openings, and in environments similar to these.

[4] Symphyotrichum pilosum is categorized on the United States National Wetland Plant List (NWPL) with the wetland indicator status rating of Facultative (FAC) in the Atlantic and Gulf Coastal Plain (AGCP) and the Eastern Mountains and Piedmont (EMP) regions.

It is categorized Facultative Upland (FACU) in the Arid West (AW), Great Plains (GP), Midwest (MW), Northcentral and Northeast (NCNE), and Western Mountains, Valleys, and Coast (WMVC) regions.

Rating FACU means that it usually occurs in non-wetlands within its range, but can occasionally be found in wetlands.

pringlei[33] and its cultivar 'Ochtendgloren'[34] have both won the Royal Horticultural Society's Award of Garden Merit.