316 THE JOURNAL OF BOTANY 



Sydney Botanic Gardens, to whom I am indebted for the 

 opportunity of examining the specimens. 



Maidenia 



Hydeocharidacearum e tribu Vallisneriearum genus novum. 



Flores dioici, spathacei. Spatha mascula bivalvis, breviter 

 pedunculata, ovoidea, stamina plurima in axe erecto spiraUter 

 aggregata includens. Staminis filamentum breve, tenue ; anthera 

 late ellipsoidea, bilocularis. Spatha foeminea bifida, uniflora, 

 pedunculo longissimo fiHformi. Perianthium simplex, ad basin in 

 segmentis tribus subaequalibus petaloideis divisum. Staminodia 0. 

 Ovarium inferum, subcylindricum, e spatha protrusum, uniloculare; 

 stigmata 3, segmentis perianthii alternantia et subaequantia, lata, 

 bifida ; ovula numerosa, parietalia, orthotropa, erecta vel ascen- 

 dentia, quidque tegumento singulo indutum. Fructus (immaturus) 

 fusiformis, obscure tricarinatus, basi a spathae reliquis cinctus, 

 pericarpio tenui. Semina numerosa, minuta. 



Herba parva submersa, caule tenui, basi radicante et interdum 

 stolonifero, erecto, simplici, undique dense foHoso. Folia alter- 

 nantia, conferta, anguste linearia, margine et apice sparse spinifera, 

 basi vix vaginata. Spathae masculge in axillis foliorum vicinorum 

 pseudoverticillatoe. Spathae foemineae numerosas, plures in pro- 

 pagulis axillaribus sessilibus pseudoverticillatis ordinatae, florentes 

 emersae, post anthesin spiraliter retractae et sub aqua maturescentes. 



Species 1, in Australia boreali-occidentale. 



M. rubra, sp. unica. Herba 5-6 cm. alt., caule simpHci usque 

 ad 2 mm. crasso. Folia 2 vel saepius 3-4 cm. longa, basi caulis 

 •8-1-3 mm. lata, alibi 4 mm. lata, superne setacea, apice et margine 

 spinulis brunneis sursum versis instrncta. Spatha mascula 2*5 mm. 

 longa, pedunculo brevissimo. Spatha foeminea 2'5 mm. longa, 

 lobis obtuse rotundatis vix 1 mm. longis, pedunculo 2-3 cm. lougo ; 

 flos purpureus, 3 mm. longus, perianthii segmentis late ellipticis, 

 vix 1 mm. longis. Fructus (immaturus) 4 mm. longus. 



Hab. West Australia ; near King river. East Kimberley. 



Coll. W. V. Fitzgerald, October, 1906. 



Description of Plate. 



1. Portion of female plant, nat. size. 2. Group of female flowers with two 

 enveloping sheathing leaves (somewhat diagrammatic), x 8. 3. Female flower 

 in its spathe, x 16. 4. Young fruit, x 5. 5. Portion of inner face of same 

 with ovules, x 16. 6. Cross-section of same showing the three ridges on the 

 outer wall, x 20. 7. Ovule (after pollination), x 35. 8. A male plant with 

 basal tuft of roots and a stolon, nat. size. 9. Pseudo-whorl of male spathes, x 4. 

 10. Single male spathe, x 16. 11. A male spathe with vahes separated showing 

 axis bearing an'.hers, x 20. 12. Anther, the division of tiie pollen-mother-cells 

 is indicated, x 85. 13. Portion of leaf-surface, showing spines on margin, x 20. 

 14. Apex of leif, x 20. 



