291 

 1— APONOGETON. 



1. A monostachyon, Linn. f. ; Hook. f. Fl. Brit. Ind. vi. 564. 

 Hongkong New Territory without locality ; pools near 

 Canton. Fl. white, August. 



2.— POTAMOGETON. 



Key to species. 



Leaves flat, ovate 1. Gaudichaudii. 



Leaves crisped, linear 2. crispus. 



1. P. Gaudichaudii, Cham, et Schhcht. ; P. mucronatus, Presl ; 



Hook. f. Fl. Brit. Ind. vi. 567. Canton. Fl. green. 



2. P. crispus, Li7in. ; Hook. f. 1. c. 566. Pond near Swatow. Fl. 



pink, April. 



3.— RUPPIA. 



1. R. maritima, Linn. ; R. rostellata, Koch ; Hook. f. 1. c. 568. 

 Sheko Lagoon, Hongkong. Fl- January. 



4.— ZANNIGHELLIA. 



1. Z. pedicellata, Ham. ; Z. palustris, subsp. pedicellata. 

 Hook. f. 1. c. 568. Near Swatow. Fl. white, April. 



5.— NAJAS. 



I. N. graminea, Delile ; N. minor, Benth. Fl. Hongk. 345. 

 Hongkong without locality. Fl. . 



ERIOCAULONACEAE. 



2. 



1.— ERIOOAULON. 



Stem elongated .. . 



Stem not elongated 



Involucral bracts longer than the flowers 



Involucral bracts not longer than the 



flowers 



3. Leaves pillose ... 

 Leaves glabrous 



4. Involucral bracts villose 

 Involucral bracts glabrous 



5. Sepals of male flowers dimerous 

 Sepals of male flowers trimerous 



6. Floral bracts acute 



Floral bracts obtuse 



2. 



5. 



6, 



setaceum. 



2. 

 echinulatum. 



3. 



australe. 



4. 

 Mlghtianum. 



5. 



6. 



7. 

 sinicum. 

 truncaUmi. 



21515 



T 2 



