Mathewsiane. N. O. Filices. 
TAB. CXIX. 
PTERIS FLEXUOSA. 
Fronde bi- subtri-pinnata, pinnulis petiolatis cordato-ovatis ob- 
tusis, rachidibus omnibus insigniter flexuosis junioribus pubes- 
centi-hispidis, soris ad margines laterales continuis vix ad 
apicem attingentibus. . 
Has. Province of Chacapoyas, Peruvian Andes. Mathews, 1836. 
Filiz spithameea ad pedalem et ultra. Stipes digitalis, teres, 
fuscus, nitidus. Frons circumscriptione ovato-lanceolata, bi- 
inferne subtri-pinnata ; pinnis primariis deflexis, longioribus 
3—4 pollicaribus; pinnulis remotis, lateralibus deflexis, 
terminali recta, omnibus cordato-ovatis subcoriaceis, glabris, 
obtusis, integerrimis, obscure costatis, aveniis, brevi-petiolatis. 
Rachides omnes insigniter angulato-flexuose, primaria pre- 
cipue; secundaria pubescenti-hispida. Sori continui, ad mar- 
gines laterales pinne siti, sed vix ad apicem attingentes. 
A most distinct species of a very extensive Genus (of which 
Dr. Agardh, son to the learned Algologist, is now preparing a 
monograph) remarkable for the very flexuose or zigzag rachis, 
especially the primary one: the secondary ones are less distinctly 
so, but they are singularly deflexed. 
Fig. 1. Portion of a rachis with a pinna, seen from beneath: 
—magnified. 
