266 BOTANY FOR BEGINNERS CHAP. 



those on the outside, ray flowers. The disc flowers are 

 incomplete but perfect (p. 178), actinomorphic, tubular, and 

 minute. The ray flowers are incomplete, imperfect, zygomorphic, 

 ligulate, and minute. 



Calyx. Absent in both disc- and ray-flowers. 



Corolla. Thedfof- flowers are gamopetalous, 5 lobed,epigynous. 



The nzy-flowers are gamopetalous, 3 lobed (may consist of 

 five petals), epigynous. 



Andrcecium. The dEw-flowers stamens, syngenesious, 5, 

 epipetalous. 



The ray-flower, stamens absent. 



Gyncecium. In both ray- and dw-flowers Syncarpous, 

 carpels 2, inferior, style 2-fid. 



Pollination. The disc-flowers are protandrous. The pollen 

 from them accumulates in the tube formed by the united 

 anthers. The style branches possess hairs on their outer 

 surfaces and these, when the style pushes its way up the tube, 

 act like a paint brush and sweep the pollen out. The insects 

 are attracted to the head by the ray-flowers, which make the 

 head very conspicuous. The insects creeping over the surface of 

 the inflorescence carry pollen from inflorescence to inflor- 

 escence, and cross-pollination takes place. If not pollinated 

 in this way, the style turns down and touches the pollen, and 

 self-pollination takes place. 



Description of a typical member of Liguliflorse. 

 ( Taraxacum Dens-leonis, Dandelion.) 



Habit. A perennial herb which contains a milky fluid ; 

 radical leaves, and a hollow radical peduncle, carrying a head of 

 bright yellow flowers. 



Stem. A short tap-root, is capped with a short erect 

 rhizome. 



Leaves. Radical, simple, runcinate. 



Inflorescence. Indefinite, head of from 100 to 200 flowers. 



Bracts. The Bracts form an involucre. 



Flower. Complete, zygomorphic, ligulate, small, yellow. 



Calyx. Represented by a pappus of hairs. 



Corolla. Gamopetalous, 5 lobed, epigynous. 



Androecium. Syngenesious, 5, epipetalous. 



Gynoecium. Syncarpous, carpels 2, inferior, style 2, stigma 



2-fid. 



