ROBINSON: PTERIDOPHYTA OF THE HAWAIIAN IsLAnps 199 
Baldwin 89a B; 89c B; 89 C; Bailey C; Douglas 69 B, C; Gaudi- 
chaud B; Lydgate B; Wilkes Expedition B, C. 
Polypodium pellucidum is extremely polymorphous, as is shown 
by the several nominal species that have been segregated at dif- 
ferent times. Kaulfuss’s type in the Berlin herbarium is very 
coriaceous and has the intermediate veinlike striations mentioned 
by this author. The pinnae are rather acute, 4-5 cm. long, with 
crenate-undulate margins. Divergences from this are seen in: 
(1) P. Helleri Underw. (type Heller 2602) with longer thinner 
pinnae; a single incomplete leaf has greatly elongated pinnae; 
(2) P. hawatiense Underw. with broader (1.5 cm.), shorter (3-4.5 
cm.), rounded pinnae, Hillebrand’s var. opacum from Molokai; 
(3) P. myriocarpum (Hook. Ic. Pl. 1: pl. 84) apparently a mon- 
strous form with great variability in the pinnae of the same leaf; 
(4) a form still more common in collections, which has close 
or spaced pinnae ranging from rounded to pointed on the same leaf. 
Near the extinct craters, about a mile from the Volcano House, 
Hawaii, the leaves are folded ventrally upon the midrib. A field 
study of the range of variations of the species would form an 
interesting local problem. 
POLYPODIUM HYMENOPHYLLOIDES Kaulf. Enum. Fil. 118. 1824 
Amphoradenium minutum Desv. Prod. 336. 1827. 
Adenophorus hymenophylloides Hook. & Grev. Ic. Fil. pl. 176. 
1829. 
TYPE LocaLity: Hawaiian Islands. 
DIsTRIBUTION: Rare, on trees at elevations of 1,000-1,600 m., 
Hawaiian Islands. 
ILLustrations: Gaud. Voy. Freyc. Bot. i. 8. 
Ic. Fil. pl. 176. 1829. 
SPECIMENS EXAMINED: Hawaii, Robinson 276 V; forest above 
Cape Lua Pele, Wilkes Expedition N; Wilkes Expedition 19 B, Cc; 
Maui, Robinson 347 V; Wilkes Expedition B, C, N; Oahu, Beechey 
C; Diell C; Robinson 87 V; 97 V; Kauai, Heller 2213 C, N; 
Knudsen 154 B; Robinson 462 V; Hawaiian Islands, Baldwin go 
B, C, N; Gaudichaud B, C; Hillebrand B; Mann & Brigham 276 N. 
Hook. & Grev. 
