GARDEN BOTANY. 



Ivii 



No strap-shaped flowers, but with a ray of enlarged and cleft 



tubular flowers 



Flowers all tubular and alike : scales of the involucre fleshy. 

 Pappus of several, or more than 2, conspicuous chaffy scales, 



which are often awned or bristle-pointed. 

 Rays none : flowers all alike, tubular, mostly blue. . 

 Rays or marginal strap-shaped flowers conspicuous, yellow, or 



partly brown or purple. 



Involucre of separate leafy scales : leaves not punctate. 

 Involucre a solid cup : strong-scented herbage glandular- 

 punctate with coarse pellucid dots 



Pappus none, or a small cup, or of only 2 teeth, scales, or awns. 

 Heads with rays or larger strap-shaped flowers round the mar- 

 gin, or in cultivation sometimes all the corollas changed 

 into such (double) flowers. 



Achenia incurved, rough, not flattened : flowers yellow. 

 Achenia not incurved except in Coreopsis. 



Involucre double, of few scales, the outer different from 

 the inner, each in one row or nearly : leaves opposite. 

 Ray-flowers many in the cultivated varieties. 

 Ray -flowers, 6 or 8, broad, neutral : achenia compressed. 

 Involucre not double, but usually imbricated. 

 Receptacle bearing chaffy scales among the flowers. 

 Rays persistent without fading, paper-like, pistillate. 

 Rays not persistent, 



Neutral : pappus of 2 deciduous chaffy scales. 

 Neutral : pappus a little cup or none. Man. p. 214. 



Pistillate, numerous, elongated 



Pistillate, few, short and broad. . . 



Receptacle naked, i. e. no chaff among the flowers. 



Receptacle conical 



Receptacle flat or convex. 



Heads without any obvious rays, 



Rose-colored or white : a quilled state of the Daisy. . . 

 t Orange, large, with a leafy and spiny involucre. 

 Yellow or greenish, small, not prickly : strong-scented plants. 

 Pappus a minute cup or none : heads hemispherical. 

 Pappus none : heads globular, very small. ... 



18. CENTAUREA. 



19. CYNARA. 



1. AGERATUM. 



8. GAILLARDIA. 



9. TAGETES. 



10. CALENDULA. 



6. DAHLIA. 



7. COREOPSIS. 



4. ZINNIA. 



6. HELIANTHUS. 

 RUDBECKIA. 



12. ANTHEMIS. 



13. ACHILLEA. 



3. BELLIS. 

 11. CHRYSANTHEMUM. 



3. BELLIS. 

 17. CARTHAMUS. 



14. TANACETUM. 



15. ARTEMISIA. 



* * Juice of the stem milky : flowers all perfect and with strap-shaped corollas. 



Pappus a row of many short scales united into a cup or crown : 



flowers 20 or less, blue, ephemeral. . Man. p. 235. CICHORIUM. 



Pappus of 5 to 7 long and pointed scales : scales of the involucre 



scarious, imbricated : flowers blue. . ... 20. CATANANCHE. 



Pappus of many strongly plumose stout bristles : achenia long- 

 beaked : flowers purple or purplish 21. TRAGOPOGON. 



Pappus a tuft of soft and white smooth hairs : achenia flat, with 



a long and slender beak : flowers yellow. ... 22. LACTUCA. 



1. Ageratum conyzoides, var. Mexicanum, is a tender annual, with 



ovate and cordate pubescent and veiny opposite leaves, and loose corymbs of 

 small heads of sky-blue flowers ; the most prominent part of these consists 

 of the club-shaped styles. 



