11 



OS. AXOL.L.A. Lnmtu-ch. 



Sporacarps in groups of 2 4, placed at the base of a rhizome branch, 

 provided with a central, columnar placenta bearing the sporangia ; microspo- 

 rangia long-stalked, the stalk consisting of 2 rows of cells; macrospores 

 provided at the apex with 3 or 9 air-filled floats; microspores united in 

 several separate, roundish or ovate masses (massulae) each of which con- 

 taining 4 8 spores. 



Leaves very small, borne in 2 opposite rows, alternate, deeply 2-fid, 



nearly 2-foliate; lobes heteromorphous, the lower one submerged, the 



upper floating, having at the inner side a cavity which is provided with 



fine moniliform files. Fine roots borne on the under side of the rhizome. 



- Engl. & Prantl, Nat. Pfl.Fam., I 4 , fig. 208, 212 A. 



Tropical, subtropical and in temperate regions. 



Arrangement of the sections. 



1. RHIZOSPERMA. Macrospores with 9 floats ; massulae not glochidiate. 



2. EU-AZOLLA. Macrospores with 3 floats; massulae glochidiate. - 

 Engl. & Prantl, 1. c., fig. 215 B. (Not in Malaya). 



1. RHIZOSPERMA. 



(1) A. pinuata. K. Hr., Bk., Fern AIL, 138; Flind., Voy., tab. X; 

 - var. africana, Bk., 1. c. ; A. africana, Desv., Copel., Philipp. Journ., IV C , 

 14; A. japonica, Fr. & Sav., En. Jap., II, 195. 



The whole plant oblong or deltoid in outline, IVa 2 'A cm. long and 

 broad, with regular, crowded branches; branches simple, or branched 

 towards the tip; root-fibres fascicled and very feathery. Leaves red or 

 green, with the lobes broadly ovate, at best a few mm. long. 



Forma typica. Australia. 



War. africana: Plants smaller, 1 cm. long and broad, with 

 rather irregular branches ; root-fibres, at least usually, not feathery, not 

 fascicled. Tropical Africa and Asia, Japan. 



