36 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Cuba: Monte Verde, Oriente, Wright 832. 



Jamaica: Clyde River Valley (below Cinchona), altitude 900 to 1,200 meters, 

 Underwood 428, 429, 430, 442, 2644, 2645, 2648, 2649; Maxon 1595, 1599; 



Harris 7161. Without exact locality, Hart 29, 32a. 



15. Polystichum rhizophorum (Jenman) Maxon. Plate 7, 

 -4s pidium viviparum rhizophorum J enman, Bull. Bot. Dept. Jamaica 11,2: 268. 1895^ 

 Plants of relatively small stature, fronds 20 to 35 cm. long, closely fasciculate, sub- 

 dimorphous, the fertile ones usually erect and noncaudate, the sterile ones flagellate- 

 radicant and mostly horizontally arching. Rhizome slight, usually 5 to 7 mm. in 

 diameter, 2 to 2.5 cm. long, erect or ascending, clothed sparingly with dull light brown- 

 ish ovate scales; stipe slight, sulcate or somewhat compressed, greenish, with notice- 

 able scales at the base like those of the rhizome, otherwise glabrescent, in the sterile 

 fronds measuring 1.5 to 11 cm. long (average about 4 cm.), in the fertile frond 7 to 12 

 cm. long (average 10 cm. or more); rachis compressed and very narrowly alate; lamina 

 of the sterile frond 30 to 45 cm. long, 3.5 to 5.5 cm. broad, simply pinnate or rarely 

 again deeply pinnatifid, narrowly lanceolate, subarcuate in drying, the pinnae approxi- 

 mate or somewhat spaced, the upper ones reduced and giving way (sometimes 

 abruptly) to a slender pliant radicant cauda 8 to 18 cm. long; lamina of the fertile 

 frond linear-lanceolate, 15 to 25 cm. long (average near the minimum), about 2.5 cm. 

 broad, usually erect and noncaudate, the pinnte distant; pinnae of both sterile and 

 fertile fronds slightly scurfy below, subtriangular-trapeziform, auriculate at the upper 

 base, the auricle subspinescent, the margins otherwise usually not spinescent but 

 ranging from subentire to obliquely biserrate, the inferior margin widely excised at 

 the base; sori 5 to 7 pairs to the pinna, rather nearer the mid vein than the margin. 



Jamaica: Vicinity of Hollymount, Mount Diabolo, altitude about 750 meters, 

 Maxon 1912, 1932, 2277, 2356; Underwood 3442. Without locality, Jenman 

 (two sheets). 



The present species, which seems to be confined to Jamaica, was described briefly 

 by Jenman as a subspecies of the Jamaican "viviparum'' (P. dissimulans sp. nov. of 

 the present paper), to which species it appears to have no very near relationship. It 

 has, according to Jenman, rather a wide distribution in Jamaica; but the writer has 

 collected it at only one station (there, however, in quantity), where it shows unmis- 

 takably the characteristic form described by Jenman. It grows, at Hollymount, in 

 firm rocky ground or in crevices of rocks, always in the humid forest. It was never 

 observed to occupy the more open situations favorable to P. triangulum, which grew in 

 the same general locality. 



Jenman's comment on this form is in part as follows: u This resembles Polypodium 

 reptans Sw. in habit, the fertile fronds being erect, devoid of a tail, as a rule, and with 

 the petioles twice as long as those of the barren ones. In the latter the upper pinrne 

 become gradually more distant to the uppermost of all, terminating abruptly." The 

 writer has seen only a slight approach toward the bipinnate form mentioned by 

 Jenman. 



The closest relationship of /'. rhizophorum is with the Cuban form herein described 

 as P. decoratum and is discussed under that species. 



Explanation of Plate ".—Specimen from I lolly mount, Jamaica, Maxon 1912. Scale about 2. 



16. Polystichum rhizophyllum (Sw.) Presl, Tent. Pterid. 82. 1836. 

 Poly podium rhizophy Hum Sw. Prodr. 132. 1788. 



Aspidium rhizophyllum Sw. Schrad. Journ. Bot. 1800 2 : 31. 1801. 

 Polystichum krugii Maxon, Proc. Biol. Soc. Washington 18: 215. 1905. 

 The present species was described originally from Jamaica and was figured later 

 upon Jamaican specimens by Hooker and Greville." It has been attributed also to 



« Hook. & Grev. Ic. Fil. 1: pi. 59. 1829. 



