TAB. CXLV. 
ACROSTICHUM DIMORPHUM. 
FILICES.—GvnaTxz. Br.  Porvropnraczm. Kaulf.  FirrCEs verw. Willd. 
GrN. Cuag. 4CROSTICHUM, Linn. Sori amorphi, seu Capsule per totam paginam infe- 
riorem frondis (interdum diversc) l. ad ejus partem sparse.  Zmvolucrum nullum (nisi squa- 
mule vel sete in quibusdam capsulis interstinctze). Br. 
ACROSTICHUM dimorphum ; frondibus simplicibus lanceolatis obtusis profunde serrato-dentatis, fer- 
tilibus integerrimis, stipite longo squamoso. 
Has. Ex Insula Sancte Helene misit 74ez. JZ"alker, phus Praefectus. Apud Madras legit 
— Shuter, M.D. 
Caudex repens, subcrassus, valde squamosus, radicosus, radicibus fibrosis ramosis nigro-fuscis. " 
Stipites digitales et ultra, erecti, flexuosi, subnitidi, graciles, hinc canaliculati, paleacei, squamis sparsis, fuscis, 
patentibus. : 
Frondes lanceolatze, obtusz, basi attenuatz, coriaceo-membranaces, costatee, 
venoss, venis furcatis, obliquis: 
steriles digitales ad palmares, subpellucidse, virides, 
margine ubique grosse et ins;equaliter dentato-serratze : 
Jertiles minores, duas ad tres uncias longze, coriaceze, fuscze, margine omnino integerrimze. 
Capsule totam inferiorem partem frondis tegentes, fuscae, globose, brevi-stipitatze. 
Semina, subglobosa, tuberculata, fusca. 
Fig. 1. Frondes steriles. f. 2. Frondes steriles cum fertili. f. 3. Capsule. f 4. Semina:—omagn. auct. 
It is singular that this Fern, one of the most distinct in the genus zerostichum, and which I have 
received from Brigadier-General Walker, the late Governor of St. Helena, gathered in that island, 
and from the late Dr. Shuter, gathered at Madras, should never have been described by any Botanist. 
It is remarkable for its deeply and irregularly toothed margin, for the strong veining and semi- 
transparency of the barren frond; whilst the fertile one is quite entire at the margin, 
to that of many other simple-fronded species of the genus. 
and similar 
