1180 CARDUACEAE 
23. GRINDELIA Willd. 
Perennial or rarely annual or biennial herbs, or shrubby plants, usually with glabrous 
or glutinous foliage. Leaves alternate: blades mostly spinulose-toothed, sessile or clasp- 
ing. Heads relatively large, radiate or rarely discoid, often in corymbs. Involucreg 
hemispheric or depressed, many-flowered : bracts in several series, usually with subulate 
tips. Receptacle pitted. Ray-flowers pistillate, fruit producing, rarely wanting. Disk- 
flowers perfect or sometimes staminate. Stigmas narrow, flattened, with linear or lanceolate 
appendages. Achenes 4—5-ribbed, sometimes flattened. Pappus of 2-8 awns or bristles, 
early deciduous. GUM-PLANT. 
Stems pubescent, at least above. 
Involucres less than 1 cm. broad. A 1. G. microcephala. 
Involucres over 1 cm. broad. 2. G. inuloides. 
Stems glabrous throughout. 
Achenes without teeth or auricles at the top. 
Involucres less than 1.5 em. broad: leaf-blades with gland-tipped teeth. 3. G. squarrosa. 
Involucres over 1.5 cm. broad : leaf-blades with very sharp, sometimes spinu- } 
lose, teeth. 4. G. grandifiora. 
Achenes with 1 or 2 teeth or auricles at the top. 5. G. lanceolata. 
1. Grindelia microcéphala DC. Stems minutely pubescent, 2-5 dm. tall, branched. 
Leaf-blades oblanceolate to oblong or oblong-ovate, 1-4 cm. long, acute or acutish, closely 
toothed to the partly clasping base, the teeth gland-tipped : involucres 5-7 mm. high ; bracts 
linear or nearly so, with green spreading tips : achenes 3 mm. long, oval, mdged. 
On plains, Texas. Spring and summer. 
2. Grindelia inuloides Willd. Stems minutely pubescent, 3-7 dm. tall, simple or 
sparingly branched. Leaf-blades oblong, oblong-lanceolate or nearly ovate, or sometimes 
broadest above the middle near the base of the stem, 1.5-5 cm. long, acute, closely toothed 
to the partly clasping base, the teeth gland-tipped: involucres about 1 cm. high; bracts 
linear or nearly so, with green spreading tips: achenes 4 mm. long, broadest near the 
rounded truncate top. 
On plains, Arkansas and Texas. Summer and fall. 
3. Grindelia squarrdsa (Pursh) Dunal. Stems glabrous, 3-8 dm. tall, branched 
above. Leaf-blades oblong-spatulate to oblong, 2-5 em. long, acutely or spinose-serrate, | 
partly clasping: heads sometimes numerous: involucres about 1.5 cm. broad, glutinous ; 
bracts linear-lanceolate, prolonged into slender leathery tips, the inner erect or ascending, 
the outer spreading or recurved: ray-flowers usually present; ligules bright yellow: 
achenes with 2-3 pappus-awns. 
In dry soil, Minnesota and Manitoba, to Illinois, Texas, Nevada and Mexico, Summer and 
4. Grindelia grandifldra Hook. Stems glabrous, pale red and shining, 5-12 dm. tall, 
usually simple below. Leaf-blades lanceolate to oblong-ovate or ovate, 1.5-5 cm. long, 
sharply and closely toothed, sessile, or the upper ones partly clasping : heads showy : mvo- 
lucres about 1.5 em. broad, 1 em. high; bracts linear-lanceolate to linear: ray-flowers 
present ; ligules yellow, 1.5-2.5 cm. long: achenes with 2-3 pappus-awns. 
On plains and prairies, Texas. Spring and summer. 
5. Grindelia lanceolàta Nutt. Stems 5-8 dm. tall, glabrous, sparingly branched 
above. Leaf-blades lanceolate to linear-lanceolate, 2-8 cm. long, acute or slightly Acupuc 
nate, sessile, serrate, sometimes shallowly so, or those near the base of the stem laciniate : 
heads showy: involucres about 1.5 em. broad ; bracts produced into linear-filiform tips, 
the outer bracts with spreading tips: achenes with 1-2 tooth-like pappus scales at the top. 
On plains or prairies, Missouri and Kansas to Tennessee, Louisiana and Texas. Summer. 
fall. 
24. HETEROTHECA Cass. 
Annual or biennial caulescent herbs, with pubescent foliage. 
blades flat, entire or toothed, commonly sessile above the base of the stem. Heads ra 
showy, in panicles. Involucres hemispheric or campanulate, many-flowered : bracts nar- 
row, in several series, the inner successively longer. Receptacle flat, pitted. . Ray -flowers 
pistillate. Disk-flowers numerous, perfect, or some of them staminate. Corollas dapes 
Stigmas with triangular or lanceolate appendages. Achenes various, those of the dis 
more flattened than those of the ray. Pappus various, that of the ray of few caducous 
bristles, or obsolete, that of the disk double, the outer of scales or stout bristles, the 1nner 
of numerous rough hair-like bristles. 
Leaves alternate: 
diate, 
