360 GLOSSARY OF TERMS USED IN THIS BOOK. 



Sympodial, said of types of branching where the lateral axes grow more rap- 

 idly than the main axis, 227. 



Syncarpous, said of the gynoecium when the carpels are united, 229, 230. 



Testa, the outer coat of the seed, 208, 210. 



Thallophytes, plants of low organization in which the plant body is a frond 

 or thallus, especially the algae and fungi, 217. 



Tropophytes, plants, especially of the North Temperate Zone, which have 

 hygrophytic structures during the summer season, and during the win- 

 ter season change to xerophytic habit, 288, 289. 



Tubers, underground thickened stems. 219. 



Umbel, said of an inflorescence where the main axis is shortened and the 

 terminal flowers appear to form terminal clusters, 227. 



Xerophytes, plants adapted to grow in dry situations, or in situations where 

 they absorb water with difficulty, 288, 289. 



Xylem, the woody elements of the fibrovascular bundle, 64-68. 



Zygospore, zygote, a resting spore, formed by the sexual union of two equal 

 or nearly equal cells, 117, 118. 



