224 Key to the System of 



FIIVIELEA. 



1049. Leaves mostly or all scattered ... ... 1050 



Leaves mostly or all opposite ... ... ... 1054 



1050. Involucral bracts two to four ... ... ... 1051 



Involucral bracts more than four ... ... ... 1053 



1051. Flowers in spikes. 



Annual, dwarf, but quite erect ; leaves small, from elliptic- 

 to broad-linear, concave, almost or quite glabrous ; 

 irivolucral bracts four or two, similar to the leaves, early 

 deciduous ; flowers very small, all staminate and pistillate ; 

 calyx yellowish, much beset with soft spreading hairlets ; 

 fruit dry. P. trichostachya. 



Flowers in headlets or clusters ... ... ... 1052 



1052. Involucral bracts four. 



Annual, dwarf, but quite erect ; leaves small, from elliptic- 

 to broad-linear, soon glabrous, generally appressed ; 

 involucral bracts similar to the leaves, early deciduous ; 

 flowers in terminal headlets, minute, all staminate and 

 pistillate ; calyx invested with soft hairlets, yellow inside ; 

 fruit dry. P. simplex. 



Involucral bracts two. 



A somewhat shrubby plant, never tall, beset with appressed 

 often scattered hairlets ; leaves mostly linear-elliptical, 

 and scattered ; involucral bracts similar to the leaves ; 

 flowers very small, in singly terminal and also almost 

 axillary clusters, all staminate and pistillate ; calyx 

 slender, invested with appressed shining hairlets, yel- 

 lowish inside; fruit dry. P. CTirviflora. 



053. Flowers quite large. 



A somewhat shrubby plant, never tall, much beset with 

 long soft and spreading hairlets ; leaves from linear- to 

 narrow -elliptical ; involucral bracts eight or more, simi- 

 lar to the leaves ; flowers in singly terminal headlets, 

 all staminate and pistillate; calyx pale, invested with 

 rather long soft hairlets ; fruit dry. P. octophylla. 



