408 



FOURTH GROUP. SEED-PLANTS. 



J. alpinus, J. Gerardi, Luzida nemorosa, etc.) *. The anthela of these 

 genera, and those of Scirpus and Cyperus, show many different forms that 

 are transitions to the panicle and even to the spike, and on the other 

 hand also to the formation of cymose inflorescences with false axes (e. g. 

 Juncus bufonius) ; the inflorescence of Spiraea Ulmaria is included in this 

 division by myself and others. 



m 



FIG. 336. Diagram of a dichasium (false dichotomy). The Roman numerals denote the order of development 

 of the shoots of the system. The shoot / terminates with a flower and produces the shoots //' and //", etc. 



o-~ 



A. 



FIG. 337. Cicinnus or scorpioid cyme and bostryx or helicoid cyme in ground-plan and elevation. A elevation of 

 cicinnus ; each shoot ends with a flower and produces an axillary shoot alternately right (as 2) and left (as 3). B ground- 

 plan of the cicinnus. C elevation, D ground-plan of the bostryx. 



11. Cymose umbel. A whorl of three or more equally strong axes spring from 

 beneath the first flower, and these in their turn produce each a whorl of 

 lateral axes beneath the terminal flower, and the process is repeated in the 

 same manner ; the whole system has the habit of a true umbel ; very good 

 examples are to be seen in the Euphorbiaceae, especially in Euphorbia helio- 

 scopia and E. Lathyris ; this form of cyme is not essentially different from the 

 following one, the dichasium, and the cymose umbel often passes into it in 

 the higher orders of shoots, e.g. in Periploca graeca even in the first 

 branches. 



1 2. Dichasium. Each axis of the inflorescence that terminates in a flower pro- 

 duces a pair of opposite or nearly opposite lateral axes, which terminate in 

 a flower after they have in turn produced a pair of lateral axes, and so on ; 



1 Buchenau in Pringsh. Jahrb. f. wiss. Bot. IV. p. 393 and Taf. 28-30. 



