32 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Polystichum dissimulans probably embraces most of the Jamaican material included 

 by Jenman as typical of his " Aspidium riviparum," excluding the several subspecies 

 recognized by him. It is about equally related to J', triangulum and the endemic 

 Cuban /'. heterolepis, though perhaps more closely allied to the latter. From P. 

 hetcrolepis it differs in its chaff, its lesser subdivision and in mature states, its relatively 

 broader pinna? and especially in its exceedingly harsh coarse texture and long-spines- 

 cent segments. From any form of P. triangulum it is distinguished by its viviparous 

 apex and regularly free-auriculate pinna;. It is the most rigid of all the middle Amer- 

 ican species of Polystichum. , 



Explanation of Plate 4, Figure A.— Middle portion of type specimen. Natural size. 



6. Polystichum guadeloupense Fee, Time Mem. Foug. 74. pi. 19. f. 2. I860. 

 This must be regarded as a very doubtful species. The type, collected by L'ller- 



minier from rocks along the sea shore in some part of Guadeloupe, indicates, accord- 

 ing to Fee's diagnosis and illustration, a species unique in the triangulum group in its 

 sharply erose-dentate (scarcely spinulose) margins, in this character resembling young 

 plants of Stenochlaena kunzeana (Presl.) Underw. A small specimen collected in 

 Guadeloupe by Buss (no. 4343), in the herbarium of the New York Botanical Garden, 

 isapparently the same. But this scarcely differs more from the Greater Antilles speci- 

 mens of P. triangulum than the specimens of undoubted triangulum do among them- 

 selves, suggesting that it may be only a small delicate form of the well-known species. 

 If it does attain a larger state in Guadeloupe it is strange that it should not have been 

 collected by Duss. More complete collections in future may perhaps establish its 

 claim to rank as a distinct species. It is so recognized by Christensen, whether or 

 not on the basis of specimens actually examined the writer docs not know. 



7. Polystichum harrisii Maxon, nom. nov. Plate 4, Figure P. 

 Aspidium, caudatum Jenman, Journ. Hot. 8: 260. 1879, not A. caudatum Sw. 1806, 



nor Sw. 1817. 

 Aspidium viviparum caudatum Jenman, Bull. Bot. Dept. Jamaica II. 2: 268. 1895. 

 Jenman 's original description of this species is accurate, except that the under 

 surfaces may be said to be very sparingly and minutely scaly, glabrescent instead of 

 glabrous. The numerous large scales of the rhizome and lower stipe are membranous 

 and of a rich brown color, never (in the specimens examined) blackish and glossv as 

 in the various forms of triangulum. 



Confined to Jamaica and said by Jenman to be "frequent in the western parishes, 

 Manchester, Clarendon, etc., above 1,500 or 2,000 feet altitude." 



Jamaica: Vicinity of Troy, altitude 600 to 660 meters, in rocky forests, sometimes 

 in clefts of rocks, Maxon 2848, 2862; Underwood 2963. Tyre (near Troy), 

 Cnderivood 3W9, 3310. Without locality, Jenman (4 sheets labeled Aspidium 

 caudatum). 

 The name is given in honor of William Harris, esq., superintendent of Hope Gardens, 

 Jamaica, in grateful acknowledgment of courtesies extended to the writer in many 

 ways during his field work in Jamaica in 1903 and 1904. 

 The type, collected in 1878, is at Kew. 



Explanation of Plate 4, Figure B.— Middle portion of a specimen from Troy, Jamaica, Maxon 

 2848. Natural size. 



8. Polystichum heterolepis Fee, Gen. Fil. 279. 1850-1852. Plate 5. 

 J'olyslichum riviparum Fee, Gen. Fil. 280. 1850-1852. 



Aspidium viviparum Mett. Abhand. Senck. Nat. Gesell. 2: 328. 1858. 



Fronds several, chartaceo-coriaceous, elongate (75 cm, long, maximum), long- 

 stipitate, conform. Rhizome stout, woody, ascending, thickly covered with chaff of 

 two kinds, the one linear, flaccid, fulvous, the other ovate, rigid, carinate, dark, 

 lustrous, with fulvous borders; stipe 20 to 30 cm. long, light greenish brown, deeply 

 canaliculate, rather closely covered with slender spreading fulvous scales (appressed 



