The Flowering and Fruiting of Pectinella 

 Antarctica {cymodocea Antarctica). 



By J. M. Black. 



[Read April 10, 1913.] 



Plate I. 



Pectinella, gen. novum. Flores unisexuales, solitarii, basi 

 vaginante f oliorum inclusi ; flos masculus nudus ; 

 antherae 2, quadriloculares, leviter cohaerentes, ped- 

 unculo communi insertae, polline filamentoso ; flos 

 femineus saepius bracteolis membranaceis plus minus 

 connatis absconditus ; carpella gemina, non pedi- 

 cellata sed pedunculo communi inserta, in stylum 

 attenuata, stigmatibus 3 capillaribus ; carpellum fructi- 

 ferum subdrupaceum, mesocarpio carnoso, endocarpio 

 corneo, in lobos 4 truncatos rigidos productum, itaque 

 perianthium quadrilobatum simulans ; embryo mox intra 

 fructum apice ramuli persistentem germinans et per basin 

 fissam styli procedens, demumque pericarpio emacerato 

 quadripartito et pectiniformi cinctus ad fundum maris 

 descendens et ibi radicans. Folia alterno-disticha, caules 

 nonnulli repentes, ad nodos radicant€s. Herbae sub- 

 mar inae. 



This genus differs from any other in Potaw.ogetonacece in 

 the structure of the anthers, the hard 4-lobed framework of 

 the fruiting carpel, and the peculiar mode of reproduction. 



Pectinella antarctica. Herba submersa, floribus dioicis,. 

 foliis apice lunatis, anthera a basi valvis 3 dehiscente, 

 connectivo in acumina gemina product©, uno carpello saepe 

 abortive. 



This plant has already received nine different names : — 

 Amphibolis zosterifolia, Agardh ; Caulinia antarctica, R. Br. ; 

 Cymodocea antarctica, Endl. ; Cymodocea zosterifolia, F. v. 

 M. ; Gi'aumuellera antarctica, Reichb. ; Kernera antarctica, 

 Schult. ; Posidonia antarctica, Spreng. ; Rwppia antarctica, 

 Labill. ; Thalai^sia antarctica, F. v. M. This multiplicity of 

 names is chiefly due to the flowers remaining unknown for so 

 long. 



It grows in salt water along the coasts of Victoria, South 

 Australia, and Western Australia, and was first recorded by 

 Labillardiere, the botanist of the expedition sent by Louis 



