56 



ORGANOGBAPHY AND GLOSSOLOGY. 



The ligulate corolla {c. ligulata) consists of five confluent petals, of which the 

 two upper join at their base only, but unite almost throughout their length with the 

 three others, as do these with each 

 other, so that the corolla has a 

 very short tube, and a limb en- 

 tirely formed of a finely-toothed 



291. Centrnnthns. 

 Flower (liiug.)- 



28<I. I.inurift. 

 Flower. 



287. Chrysanthemum. 



Flower with 

 ligulutc corolla. 



288. Foxglove. 



Flower with 

 aiiomuli.il-> corolla. 



280. Cornflower. 



Sterile floret 



(unng ). 



ligule (Chrysanthemum, fig. 287). Ligulate flowers are usually collected in an in- 



volucrate head, and are called semi-florets (semi-flosculi). A head (capitulum) 

 composed of semi-florets is called scini-Jtosculose (Dandelion); one 

 with tubular florets in the centre, and ligulate ones in the cir- 

 cumference, is rayed (c. radiutum, Chrysanthemum, Marigold). 



All other irregular monopetalous corollas are considered 

 to be anomalous (c. anomala). Of these the corolla of the Fox- 

 glove (fig. 288) resembles a thimble ; the flowers on the cir- 

 cumference of the Cornflower (fig. 289) are large, irregular, and 

 lieuter . tuO8e o f the Scabious (fig. 290) are also very irregular 



and almost labiate; and Centranthus (fig. 291) has an irregularly hypocrateriforin 



corolla, with an inferior spur to the tube. 



200. scabious, 



floret. 



THE ANDRCECIUM. 



The andrcecium (androecium) is the simple or double whorl, placed within or 

 above the corolla; the leaves composing it are called stamens (stamina). 



A complete stamen (fig. 292) consists of a petiole or filament (filamentum, F) and 

 a limb or anther (anthera, A) ; the anther is halved vertically by a median nerve, the 

 connective (connectivum, c) ; each half consists of a cell (loculus, L) formed of two 

 valves, the junction of which is marked externally by a furrow or suture. The back 

 of the anther faces the corolla, and its face is opposite the pistil. 



The cellular tissue of the anther-cells is originally soft, pulpy, and continuous ; 

 but when the anther is mature, this tissue becomes dry and powdery ; the two 

 valves then separate along the suture j the cell opens, and the parenchyma cells, 



