170 Key to the System of 



816. Inner fruit-sepals short-denticulated. 



Much branched; lower leaves elongate-lanceolar, at the base 

 rounded or angular ; floral leaves gradually smaller ; inner 

 fruit-sepals straight-pointed. B. flexuosus. 



Inner fruit-sepals with one or two very narrow lobes 

 on each side ... . ... ... ... ... 817 



817. Inner fruit-sepals very small, but with a conspicuous 



dorsal turgidity. 



Rather dwarf ; leaves from lanceolar- and hastate- to broad- 

 linear, crisped at the margin. R. crystallixrus. 



Inner fruit-sepals rather large, rhomboid, with a faint 

 dorsal turgidity. 



Rather tall, hardly branched ; root creeping ; stem hollow ; 

 lower leaves elongated, elliptical-lanceolar, lobeless at the 

 base ; floral leaves gradually narrower. "R. bidens. 



POX.VGONI7BI. 



818. Prostrate 819 



Erect or diffuse ... ... ... ... ... 820 



i 



819. Flowers axillary, few or solitary. 



Leaves very small, from narrow-spatular to almost elliptical 

 and linear ; fruit always triangular, smooth, shining. 



P. plebejum. 



Flowers in spikes or spike-like racemes. 



Beset with appressed hairlets ; stipular tube scantily cilio- 

 lated, sometimes herbaceously protracted ; leaves almost 

 lanceolar ; spikes axillary and terminal, short- stalked ; 

 flowers greenish ; fruit always biangular. 



F. prostratuxn. 



820. Flowers in abbreviated spikes. 



Somewhat beset with stiff reversed hairlets ; leaves from 

 oval to lanceolar, mostly truncate or bilobed at the base ; 

 stipular tube long- ciliolated; spikes few-flowered, reddish, 

 on dichotomous stalks ; fruit bi- or tri-angular. 



P. strigosum. 



Flowers in elongated spikes ... ... ... ... 821 



