220 



0. A. Thwaitesii, Hooh. f. in Bot. Mag. t. 4918. In bamboo 

 groves south-west of Wongneichong village, and in the 

 clefts of rocks on the north face of Mt. Nicholson, Hong- 

 kong ; Lantao Island, Hongkong New Territory. Fl. 

 purple or chocolate-coloured, March. 



PIPERACEAE. 



Key to genera. 



Flowers shortly stalked 

 Flowers sessile ... 



Leaf about equal in length to its petiole 

 Leaf many times longer than petiole 

 Spikes involucrate 

 Spikes naked 

 Erect herb 

 Woody climber 



Spikes hardly broader than the peduncle 

 Spikes three times as broad as the 

 peduncle 



o. 



3. 

 Gymnotheca. 

 Saururus. 

 Houttuynia. 



4. 



5. 

 Piper. 

 Pcperomia. 



4. Piper. 



1.— SAURURUS. 



1. S. Loureiri, Decne. ; DC. Prodr. xvi. i. 239. Grassy banks of 

 watercourses, Taitamtuk, Hongkong ; Swatow district ; 

 on muddy banks of creeks, Canton ; West Kiver above 

 Shiuhing. Fl. white. May. 



2.— HOUTTUYNIA. 



1. H. cordata, Thnnh. ; Benth. Fl. Hongk. 334. Damp shady 

 places Chaiwan, Hongkong ; wet courtyard of the White 

 Cloud monastery ; West River ; Lofoushan. Fl. white, 

 May — December. 



3.— GYMNOTHECA. 



G. chinensis, Decne. ; Hook. Ic. PI. t. 1873. 

 Fl. white, August. 



Lienchow River. 



3. 



