" Liatris squarrosa (Linnaeus) Michaux, Fl. Bor.-Amer.2: 92. 1803 · Loosescale gayfeather, olicroot Serratula squarrosa Linnaeus, Sp.Pl. 2: 818. 1753; Lacinaria squarrosa (Linnaeus) Hill Plants 30–80 cm. Corms globose to slightly elongate. Stemsglabrous or puberulent-villous.Leaves: basal and proximal cauline 3–5-nerved, broadly linear to linear-oblanceolate, 0–220 ×2–12 mm (largest usually distal to proximalmost),gradually reduced distally, puberulent-illous orglabrous, weakly gland-dotted. Heads borne singly or (3–26) in loose, racemiform to piciform arrays. Peduncles 0 or (spreading to ascending) 1–8(–20+) mm.Involucres cylindro-ampanulate, 12–20(–25) × 7–10mm. Phyllaries (usually erect, sometimes spreadingreflexing
on the distal 1/3) in 5–7 series, narrowly ovatetriangular and foliaceous (outer) to ovate or oblongtriangular,± equal, glabrous or pubescent, margins without hyaline borders, stiffly to softly ciliate, apices acuminate to acute. Florets (10–)23–45(–60); corolla tubes glabrous inside (lobes adaxially hispid). Cypselae 4–5.5 mm; pappi: lengths ± equaling corollas, bristles plumose.Varieties 2 (2 in the flora): United States.See discussion under 1. Liatris compacta1. Stems glabrous; leaves glabrous; phyllaries glabrous . . . . . . . . . . 2a. Liatris squarrosa var. glabrata 1. Stems usually puberulent-strigose (hairs soft,upturned or appressed); leaves sparsely pilose to glabrescent; phyllaries usually ciliate, faces glabrous or pubescent . . . . . . 2b. Liatris squarrosa var. squarrosa
2a. Liatris squarrosa (Linnaeus) Michaux var. glabrata (Rydberg) Gaiser, Rhodora 48: 401. 1946 Liatris glabrata Rydberg, Brittonia 1: 98. 1931 Stems glabrous. Leaves glabrous. Phyllaries glabrous. Flowering (Jun–)Jul–Aug. Prairies, dunes, flood plains,ditches, roadsides, sandy soils,sandstone hills and outcrops,gravelly hills, clay soils; 50–500m; Colo., Iowa, Kans., Nebr., Okla., Tex.Variety glabrata apparently is morphologically discontinuous from var. squarrosa where their ranges closely approach each other (but do not meet) in Texas,and they might be treated as separate species, especially in view of the treatment here of Liatris compacta at specific rank. Within var. squarrosa as treated here, plants along the Gulf coast tend to have uch reduced phyllary vestiture (var. alabamensis) and perhaps represent the precursor to var. glabrata. Involucres of var. squarrosa sometimes approach the morphology of L. hirsuta; this appears to be parallel expression of ancestral similarity, because such plants often are longseparated from the geographic range of L. hirsuta. Headstend to be more numerous and more crowded in var.glabrata than in var. squarrosa.
2b. Liatris squarrosa (Linnaeus) Michaux var.squarrosaLiatris glabrata Rydberg var. alabamensis (Alexander) Shinners;L. squarrosa var. alabamensis(Alexander) Gaiser; L. squarrosavar. gracilenta Gaiser Stems usually puberulent-strigose (hairs soft, upturned or appressed.Leaves sparsely pilose to glabrescent. Phyllaries usuallyciliate, faces glabrous or pubescent.Flowering (May–)Jul–Aug(–Sep). Oak-pine, pine,scrub oak, roadsides, fencerows, limestone outcrops,sand, sandy loam, chalk, and clay soils; 20–300 m; Ala.,Del., Fla., Ga., Ill., Ind., Ky., La., Md., Mich., Mo., N.C.,Ohio, S.C., Tenn., Va., W.Va."
Nesom, Guy L. in Flora of North America, Vol 21 Liatris p517 “Liatris Squarrosa” Oxford University Press, Inc.; New York, NY, 2006