FERNS : SYNOPTICAL LIST— VI. 



Synoptical Lid, with description, of the Ferns and Fern-Allies of Jamaica, by G. S. Jenman, Superin- 

 tendent, Botanical Gardens, Demerara (continued.) 



Tkibe IV. — Cyatheas. 



Sori subglobose, on elevated (rarely superficial) receptacles on the backs of the veins ; involucres 

 nfe nor (mostly absent in Alsophila.) 



7. Alsophila. — Involucres nearly or wholly absent. 



8. Hemitelia. — Involucres lateral, sepal-like. 



9. Cyathea. — Involucres cup-shaped or hemispherical. 



Genus VII. — Alsophila. 



Sori subglobose ; receptacles elevated or rarely superficial ; sporangia generally densely aggregated 

 and obovate cuneata, rarely few and orbicular ; involucres quite absent or rudimentary ; fronds uni- 

 formly compound, and veins free. 



This genus is distinguished by the general absence of involucres, but in several species a thin 

 microscopical film or scale exists under the sori. 



a. Fronds bipinnatifid. 

 b. Veins simple. 



1. A. sessilifolia, Jenm. 

 bb. Veins forked. 



2. A. aspera, R. Br. 



3. A. parvula, Jenm. 



4. A. infesta, Kze. 



5. A. armata, Presl. 

 aa. Frond 6 tri-quadri-pinnatifid. 



6. A. pruinata, Kaulf. 



1. A. sessilifolia, Jenm. — Stem stout, reaching several ft. high; stipites 2-2^ ft. 1. prickly ; frendg 

 ample, fcripinnatifid, 8-9 ft. 1. 3-3| ft. w., rachis stramineous, prickly ; pinnae sessile, l£-2 ft. 1. 6-8 in. 

 w. light green, paler beneath, chartaceous, slightly ciliate on the ribs and veins beneath ; pinnulas 

 apart, 3-3^ in. 1. f in. w. all quite sessile, acuminate, cut \ or f to the costulee into rather broad 

 rounded or sub-acute lobes 2-4 li. b; sori reaching to the top of the segments, rather nearer the mar- 

 gin impressing the surface on the upper side ; receptacles naked. — Journ. Bot. n. s. vol. XI. p. 325. 



Mansfield near Bath : Wilson in Herb. Kew No. 520 and in Herb. Brit. Mufe No. 513 a 1 and 

 520 ; gathered in 1858, and described in the note attached as possessing a strong prickly trunk, covered 

 with roots, 14 ft. high and 1 ft. 10 in. in circumference, the leaf and stipe together being 1 1 ft. 6 in. 1. 

 The thinner texture, pale color, sessile pinnse and simple veins distinguish it from its allies. It may 

 be a non-induaiate state of Hemitelia Wilsoni, Hook, which it very closely resembles. 



2. A. aspera, R. Br. — Stem rather slender, and of medium height, with dark coloured vestiture 

 above ; stipites few , dark, prickly beneath, 8-3£ ft. 1. clothed with bright chestnut scales, fronds tri- 

 pinnatifid, 5 or 6 ft. 1. 3-3^ ft. w. dark green, subcoriaceous ; pinnse 1^-lf ft. 1. 5-8 in. w. stipitate, not 

 close, lowest a little reduced ; pinnulse almost touching, or more or less apart, nearly or quite sessile, 

 serrulate- acuminate ; segments rounded, broadish, oblong, \-\ in. 1. 1^-2^ li. w. the edges serrulate ; 

 costse and costulse rusty pubescent above, a few dark bullate scales on the ribs beneath ; veins once 

 forked, 5-7 to a side ; sori medial, copious, situated at the forking of the veins. 



Hook. Sp. Fil. t. 19 B. ; Plum. Fil. t. 3. A. nitens J. Sm. 

 Var. major. Pinnulse, 1 in. w. 3^-4 in. 1. 

 Tar. minor. Pinnulse \ in. w. 1^-2 in. 1. 



Abounding in forests and half open situations from 1,000-4,000 ft. alt. and extending through the 

 •astern parishes. The stem is rather slender and of low density, usually 5-10 ft. high, but reaching 

 15 ft; fronds relatively large and few. The dark colour, and dark chestnut scales distinguish it at 

 sight. A slight scale-like involucre may be detected on removal of the sori by careful microscopical 

 examination. A large lax state which might be called var. arundinacea gathered by Wilson (his no. 

 689 Herb. Brit. Mus.) he describes as having several stems from a single rootstock. 



t. A. parvula, Jenm. — Stem slender, reaching 30 ft. high, scarred, clothed at the top with pale 

 scales ; stipites few or several, ft. 1. slender, curved, pale brown, with short blunt spines beneath 

 and at the base pale chaff coloured scales ; fronds 3-4 ft. 1. 1-2^ ft. w. pendent in the outer half, light 



Note. — In the sequence intended, thiB Tribe would have preceded Tribes II & III but for the loss of the MSS. in. 

 transit. 



