BY WALTER W. WATTS. 261 



V. Trke-Ferns. 



Mr. Oliver, at my suggestion, made careful notes of tlie cliarao- 

 teristies of the Tree-Ferns of the Island, and 1 am venturing to 

 reproduce his notes in their entirety. 



^'Alsophila robusta C. Moore. — Trunk smooth, with clean, dis- 

 tinct scars. Dead fronds fall away. Stipes with linear, hrown 

 scales at base. Khachis and costa? muricate througliout. No scales 

 or tomentum." [But see description below.] 



"Hemitelia Moorei Bak. — Trunk rough with broken stipes of 

 fallen fronds. Stipes covered with dense, linear scales. Rhachis 

 and base of costae with scales more or less tliickly over tlie whole 

 undersurface, and muricate below the scales; upper surface simi- 

 lar, but fewer scales and fewer prickles; costae tomentose above." 



^'Cyathea brevipinna Bak. — Trunk smooth, with clean, distinct 

 scars. A few scales at the base of the inner stipes; otherwise 

 stipes, rhachis, and costae quite clean and muricate, except costae 

 tomentose above." 



''Cyathea Macarthurii Bak. — Trunk rough with broken bases of 

 fallen fronds. Dead fronds hanging from top of trunk. Stipes 

 with long, linear, brown scales at base. Undersurface of rhachis 

 and costae muricate, and with few scattered scales, and dense 

 appressed tomentum," 



Tlie characters noted by Mr. Oliver are of the greatest impor- 

 tance in the determination of the tree-ferns, the pinnae alone being 

 often of little determinative value. 



Alsophila robusta was published in the Flora Australiensis as A. 

 australis var. nigrescens, but it is an undoubted species, and 

 Moore's name should be appropriated to this fine tree-fern. 



Alsophila robusta C. Moore, Herb. Syd.; A. australis ? var. 

 nic/rescens Benth., Fl. Austr., vii., 711. 



Caudex 8-10 ped. altus, robustus, subglaber per frondicum cica- 

 trices cadentium; stipes 3-5 dm. longus, turgidus, subglaucus, basi 

 paleis linearibus longis (ad 4 em.) vel brevibus, albescentibus ad 

 pallido-brunneis, serratis, dentibus brunneis nitentibus; frons 10-15 

 dm. longa et 6-8 cm. lata, horizontaliter pinnata; pinnae ad 40 cm. 



