Ser. Ehodosperme^. Fam. Squamariece. 



Plate LXXXI. 



PEYSSONNELIA AUSTRALIS, Sond. 



Gen. Char. Frond flat, horizontally expanded, rooting by fibrils from the 

 lower surface ; composed of two strata of cells ; the lower stratum of 

 horizontal cyhndrical cells, arranged in cohering, longitudinal fila- 

 ments ; the upper of similar cells, set in vertical cohering filaments. 

 Fnictijication of both kinds lodged in superficial warts [nemathe- 

 cia) : spores roundish, in moniliform strings ; tetraspores cruciate. 

 — Peyssonnelia [Dene.), in honour of /. A. Peyssonnel, an early and 

 meritorious observer of marine plants, especially of Corallines. 



Frons plana, Jiorizontaliter expansa, inferiore pagina radicans, stratis duohus 

 contexta ; strata inferiore cellulis cylindraceis hoizontalibus in fila longitu- 

 dinalia cohcerentia se?iatis, siiperiore cellulis similibus in fila veriicalia ordi- 

 natis constante. Triict. : utriusque generis in nematheciis evoluti. Sporce 

 subrotundce, moniliformiter seriates ; tetrasporee oblonga, cruciatim divisa. 



Peyssonnelia australis ; frond affixed at the base, otherwise free, coria- 

 ceous, dark-red, flabelliform, zoned, entire; the superior margin thin 

 and often reflexed ; the lower surface tomentose with rusty fibrils ; 

 "warts of fructification scattered, purple" {Sond.). 

 P. australis ; fronde basi solum adnata coriacea atro-sanguinea flabelliformi 

 rugoso-zonata subititegerruna ; margine superiore tenui scBpius reflexo ; pagina 

 inferiore plus minus f errugineo-tomentosa ; " verrucis fructiferis sparsis pur- 

 pur eis" (Sond.). 



Peyssonnelia australis, Sond. in Linn. v. 25. p. 685. Harv. Alg. Austr. 

 Exsic. n. 328. 



Hab. Cast up from deep water. Holdfast Bav, Br. Ferd. Mueller. Port 

 Fairy; and at Shortlands Blufi", Port Phillip, W. E. H. Bass's 

 Straits, Tasmania, Mr. C. Stuart. 



Geogr. Distr. Southern coasts, and Tasmania. 



Descr. Root a discoid attachment. Frotids one or several from the same base, 

 3-5 inches long, and nearly as broad in the widest part, cuneate at base, 

 becoming flabelliform as the lamina widens, undivided ; but often vertically 

 cloven (from accident), and then each pseudolobe, after growth is renewed, 

 becomes flabelliform like the original frond. The margin at the sides and 

 toward the base is thick and perfectly flat ; along the curved, upper edge it 

 is thin and membranous, and often folded back on the upper surface. The 

 upper side is perfectly glabrous, somewhat shining, and ridged at short in- 

 tervals with concentric wrinkles {zoned) or lines of growth. The under 

 surface is thickly clothed, except on the younger portion, near the upper 



