408 



THE KINDS OF PLANTS 



ovate-acuminate, ciliate. Minnesota to Texas and west, but everywhere in 

 gardens. 



H. rigidus, Desf. Prairie sunflower. Stout perennial (2-6 ft.), rough: 

 leaves oblong-lanceolate, entire or serrate, rough and grayish, thick and 

 rigid: heads nearly solitary, with 20-25 rays. Prairies, Michigan, west. 

 aa. Disk yellow {anthers sometimes dark). 



H. ^gant^us, Linn. Tall, to 10 ft., rough or hairy : leaves mostly 

 alternate, lanceolate-pointed, finely serrate or quite entire, nearly sessile : 

 scales linear-lanceolate, hairy: rays pale yellow, 15-20. Low grounds. 



H. divaricitus, Linn. Figs 3, 4, 23, 27. Small for the genus, 1-4 ft. : 

 leaves opposite, ovate-lanceolate, 3-nerved, sessile, serrate, rough and 

 thickish : rays 8-12, 1 in. long. Common in dry thickets. 



H. tuberdsus, Linn. Jerusalem artichoke. Bearing edible stem-tubers 

 below ground: 5-10 ft.: leaves ovate to oblong-ovate, toothed, long-petioled: 

 scales not exceeding the disk: rays 12-20, large. Penn. west, and cultivated. 



19. TANACfiTUM. Tansy. 



/.■ Tufted perennials, with finely 



divided leaves and strong odor: in- 

 volucre of overlapping dry scales: 

 torus convex : heads small, nearly 

 or quite rayless, the fiowers all seed- 

 bearing: akenes angled or ribbed, 

 bearing a short crown-like pappus. 

 T. vulgare, Linn. Common tansy from Eu- 

 rope, but run wild about old houses: 2 to 4 ft.: 

 leaves 1- to 3-pinnately cut: heads yellow, pap- 

 pus-crown 5-lobed. 



20. BIDENS. Bur-marigold. Beggar's Ticks. 



Pitchforks. 



Annual or perennial, similar to Coreopsis, 



including weeds known as Spanish-needles or 



stick -tights : leaves opposite: flowers mostly 



yellow: involucre double, outer scales large and 



leaf -like: heads many-flowered: ray flowers 4 to 



8, neutral, or none: disk flowers perfect, tubular: 



akenes flattened or slender and 4-angled, crowned 



with 2 or more rigid downwardly barbed awns. 



fronddsa, Linn. Fig. 499. Smooth or sparsely 



hairy, 2 to 6 ft. tall, branching: leaves 3- to 5-divided, or 



upper simple: leaflets stalked, lanceolate, serrate: outer 



involucre longer than head : bracts foliaceous : akenes 



wedge-ovate, flat, 2-awned. In moist places. Annual. 



B. chrysantbemoides, Michx. Smooth branching an- 

 nual, 6 in. to 2 ft., usually abundant along ditches: leaves 



