126 



MORPHOLOGY, OR COMPARATIVE ANATOMY. 



style (or a column in a staminate flower of a diclinous plant) 

 (fig. 228), the stamens are monadelphous (fig. 237), as in Malvaceae, 

 Camellia, &c. In Fumariaceas they are coherent into two equal 

 parcels, while in many Leguminosae, of ten stamens, nine are united 

 together and one free : these states are called diadelphous (figs. 

 238 & 239). In Hypericaceae we have triadelphous (fig. 240) and 

 pentadelphous states ; but these, as also the state in Aurantiaceae 

 and various Myrtaceae, are generally denominated polyadelphous, 

 and are instances of branched stamens (p. 120). 



Syngenesious signifies that the filaments are free, but the anthers 

 coherent (fig. 241), as in Compositse and Lobeliaceae. Gynandrous 

 indicates confluence of stamens and pistils, such as occur in 

 Orchidaceae, Asclepiadaceae, Aristolochia, &c. (fig. 242). These 

 terms, together with those descriptive of adhesion (perigynous, 

 epigynous, &c.), have already been explained, as also the meaning of 

 the words monoecious, dioecious, &c. 



Fig. 241. 



Fig. 242. 



Fig. 243. 



Pig. 241. Syngenesious stamens of Compositse: a, the anthers surrounding the style as a 



sheath ; b, the anthers removed and spread out, showing the free filaments. 

 Fig. 242. Section of the lower part of the perianth of Aristolochia, springing from the top of 



the inferior ovary. In the cavity of the perianth is seen the style, with the 



adherent anthers upon its sides. 

 Fig. 243. Clavate pollen-mass of Orchis, prolonged below into a caudicle, by which it attaches 



itself to the rostellum of the stigma. 



Direction of Anthers. Usually what is called the face of the 

 anther is turned inwards towards the ovary, and it is then said to 

 be introrse : but sometimes the reverse state exists, and the face is 

 turned towards the floral envelopes, as in Ranunculus, Colchicum, 

 &c., when the anthers are termed eoctrorse. Frequently the direc- 

 tion changes during the expansion of the flower, as in versatile 

 anthers. (See also under Dehiscence, p. 123.) 



Pollen. The pollen, discharged from the anthers, consists in 

 almost all cases of a fine powder composed of microscopic grains 

 or cells corresponding to the microspores of the higher Cryptogams; 



