GENUS 12. THISTLE FAMILY. 371 
12, GRINDELIA Willd. Gesell. Nat. Fr. Berl. Mag. 1: 260. 1807. 
_ Perennial or biennial herbs, sometimes woody at the base, with alternate sessile or clasp- 
ing leaves, usually spinulose-dentate, and rather large heads’ of both discoid and radiate 
yellow flowers, solitary at the ends of the branches (rays rarely wanting). Involucre hemi- 
spheric or depressed, its bracts imbricated in several or many series, usually subulate-tipped. 
Receptacle flat or convex, naked, foveolate. Ray-flowers fertile. Disk-flowers perfect, or 
sometimes only staminate. Anthers obtuse and entire at the base. Style-branches narrow, 
flattened, their appendages linear or lanceolate. Achenes short, thick, sometimes compressed, 
glabrous, 4-5-ribbed. Pappus of 2-8 soon deciduous awns or bristles. [Named for Prof. H. 
Grindel, of Riga, 1776-1836.] 
About 30 species, natives of western North America, Peru and Chile. Besides the following, 
some 15 others occur in the western and southwestern parts of North America. Known as Gum- 
plant or Tar-weed. Type species: Grindelia inuloides Willd. 
Leaves spatulate or oblong, obtuse or obtusish; achenes truncate; bracts squarrose. 
‘ : 1. G. squarrosa. 
Leaves linear or linear-oblong, acute; achenes 1-2-toothed; bracts not squarrose. 2. G. lanceolata. 
1. Grindelia squarrésa (Pursh) Dunal. Broad-leaved Gum-plant. Fig. 4192. 
Donia squarrosa Pursh, Fl. Am, Sept. 559. 1814. 
Grindelia squarrosa Dunal in DC. Prodr. 5: 
315. 1836. 
G. grandiflora Hook. Bot. Mag. pl. 4628. 1852. 
Grindelia nuda Wood. Bot. Gaz. 3: 50. 1878. 
Grindelia squarrosa nuda A. Gray, Syn. Fl. 17: 
118, 1884. 
Glabrous, erect or ascending, branched, 
102° high. Leaves oblong or oblong- 
spatulate, obtuse, more or less clasping at 
the base, sharply spinulose-dentate, some- 
times laciniate, 3’-14’ long, 3”-6” wide; 
heads 10”-15” broad, very glutinous; bracts 
of the involucre linear-lanceolate, subulate- 
tipped, strongly squarrose; achenes trun- 
cate, those of the outer flowers usually 
thicker than those of the inner; rays up to 
1’ long or wanting; pappus of 2 or 3 awns. 
_In dry soil, Illinois and Minnesota to Mani- 
toba, Missouri, Texas, Arizona and Mexico. 
Adventive in southern New Jersey, Pennsyl- 
vania and New York. June-Sept. 
2. Grindelia lanceolata Nutt. Nar- 
row-leaved Gum-plant. Fig. 4193. 
Grindelia lanceolata Nutt. Journ. Acad. Phil. 
7:73. 1834. 
Slender, erect, glabrous, branched, about 
2° high. Leaves lanceolate or linear, acute 
at the apex, sessile or clasping at the base, 
-spinulose-dentate, laciniate, or the upper 
entire, 1’-2’ long, 2-5” wide; heads nearly 
as large as those of the preceding species; 
bracts of the involucre linear-subulate, the 
inner erect, the outer spreading; achenes 
1-2-toothed; pappus of I or 2 awns. 
In dry soil, Tennessee to Missouri, Kansas, 
Louisiana and Texas. July—Sept. 
