AZOLLA.
Ord. Nat. Marsileaceæ.
Syst. Linn. Cryptogamia Filices.
Char. Gen. Flores monoici.
Masc. Gemini, involucro clauso monophyllo membranacco inclusi (nunc solitarii femineum stipantes), ovati, biloculares, membrana exteriore transversim dehiscenti: loculo superiore corpusculis 9 vel 6 angulatis, circa axin perforatum apice demum apertum insertis: loculo inferiore sphærico clauso, sub duplici membrana materia fluida (demum pulverea?) repleto.
Fem. In diversis alis ejusdem frondis solitarii (nunc masculo inferiore stipati): Involucrum duplex, utrumque clausum membranaceum: exterius marium simile: interius ovatum, evalve; includens Capsulas numerosas evalves, 6–9-spermas, affixas pedicellis capillaribus e receptaculo communi baseos involucri interioris ortis. Semina angulata, radiculis exsertis.
Azolla pinnata. Tab. 10.
Azolla fronde circumscriptione triangulari pinnata et semibipinnata; [612 foliolis superioribus papulosis, radicibus longitudinalitcr plumosis. Prodr. fl. nov. holl. 167.
In lakes and ponds, frequent within the limits of the colony of Port Jackson.
DESC. Plantula natans, facie Jungermanniæ. Radices axillares solitariæ perpendiculares hyalinæ, primo aspectu simplicissimæ, per lentem plumosæ, novellæ calyptra glabra subulata tectæ. Frons semuncialis: Ramis distichis alternis approximatis parallelis teretiusculis; infimis haud rarò pinnatis; superioribus sæpe instructis gemmulis ramulorum nonnullis axillaribus teretibus. Folia alterna undique imbricata: in latere superiore frondis trapezoideo-ovata, crassiuscula cellulosa, viridia passim rubicunda, margine exteriore submembranaceo, supra convexiuscula papuloso-scabra, subtus lævia: in latere inferiore tenuiora lævia, subconformia vix tamen angulata. Perichætia in superficie inferiore frondis, prope basin pinnæ solitaria.
Obs. Mr. Bauer's very satisfactory figure and the generic character already given, will in a great measure
