23G CERATOPTERIS. 



Hab. Tropical and subtropical regions, Asia, Africa, and America, growing in 

 quiet or slightly current waters. India: abundant in the " Gheels" and other 

 still pools, frequently such as are occasionally dry, in all the warm regions, from 

 Punjaub {Jacqiiemont), in the nortli-west to the extreme south, Wallich, Griffith, 

 Whjht, Hooker and Thomson, etc. ; and to Chittagong in the east. Hooker 

 and Thomson, and Moulmein, Rev. C. S. P. Parish; Singapore, tVaUich; Penang, 

 Norris. Java, Blume. Luzon, Brackenridge. Isle of Negros (Philippines), 

 Cuming, 71. 'i\ A. East coast of Timor, y///. Cunningham. Ladrones, Gaudichaud. 

 Hongkong, Dr. Lorraine. Tropical Australia : S. Goulburn Islands, All. Cunning- 

 ham ; Roper's River, Gulf of Carpentaria, Ferd. Mueller. Africa : " in salt waters 

 not far from the sea," Oware, Palisot de Beauvois ; turfy and marshy places, 

 Senegambia, Leprieur, Brunner. Madagascar, Boivin. Tropical America : French 

 Guiana, Richard, Leprieur ; British Guiana, C. S. Parker. West Indies : Jamaica, 

 N. Wilson; St. Vincent, Dr. Wright; Trinidad, Lockhart, Purdie. Brazil, Gard- 

 ner, n. 344, 5667, 6111, 1239, and 4397- Bahia, Saltzman. New Granada, 

 Goudot. Santa Martha, Purdie. Mexico, province of Oaxaca, Liebmann. 



This highly curious and, in form, extremely variable aquatic Fern, has been 

 greatly misunderstood as to its genus and its specific limits, and I plead guilty 

 in having myself contributed to this misunderstanding. I have constituted a 

 new Genus of what I am now satisfied is a legitimate Ceratopteris of Bron- 

 gniart, and I have made two species, both of which may safely be allowed to 

 merge into the C. thalictroides, Brongn. (the old Acrostichum thalictroides, 

 Linn.). My genus in question, Parkeria, was founded upon an aquatic Fern of 

 British Guiana, which I received from my friend C. S. Parker, Esq., in 1824, a 

 period of time when Ceratopteris was scarcely known to me, and when it was 

 only known to any one as an East Indian Fern : sufficiently so, however, I believed, 

 to justify me in constituting a new genus, and even a new Order, of Filices, 

 seeing that our plant had capsules quite destitute of annulus, while Mr. Brown 

 had recently characterized Ceratopteris, his Teleozoma, as having " capsulae 

 sessiles, annulo completo latissimo" (see Hook. Exot. Flora, under tab. 147). 

 Afterwards, on figuring the same plant in the ' Icones Filicura,' from living 

 specimens. Dr. Greville and myself detected a small and very obscure annulus, 

 of from 4-6 articulations, yet of a nature to induce our retaining the genus, 

 and even the Order ; ignorant still of Brongniart's having previously, namely 

 ill 1821, constituted his Order Ceratopterideee. On the present occasion it has 

 behoved me to reconsider my former views, with the aid of extensive suites 

 of specimens which had been accumulating in my herbarium, from the Old 

 and the New Woi'ld. These showed the most perfect uniformity of external 

 character in all, so that, unless there was a real and tangible diflerence in the 

 minute organs of fructification, there could be no possibility of distinguishing 

 them. Capsules of specimens from six. ditferent and widely distant countries 

 were submitted to the microscope, and all gradations of annulus were found, from 

 the "annulus latissimus complelus" of Mr. Brown, to capsules quite destitute 

 of ring ! Asia, Africa, and America, therefore, present one and the same 

 species. It is then, in its more perfect form, a truly and very A\%tmci\\ annulated 

 Fern, and, as such, should remain among the true Filices. Where should its 

 place then be, and what its affinities, are questions not easily answered. In 

 habit, external form, and place of growth, and in the sessile capsules, in the great 

 breadth of annulus, and above all in the few and very large and concentrically 

 striated spores or seeds,* it is entirely sui generis ; and if I place it among the 

 PteridecB on account of some affinity with Llavea and CrxjiHogramme, it is not 



* " Teleozoma insuper insigne est sporis in ordine naturali forsan, in tribu 

 quantum scio maximis obtuse trigonis pulchre striatis, puncto imico opaciore." — 

 Brown in App. Frankl. Journey, 1. c. 



