II 



FERNS : SYNOPTICAL LIST : IV. 



Synoptical List, with description of the Ferns and Fern-allies of Jamaica by G. S. Jenman, 

 Superintendent Botanical Gardens, Demerara, (continued). 

 Tribe II. Davalliew. 



Sori marginal > sub-marginal or mediul ; punctiform or transversely oblong; involucres attached in- 

 teriorly, the margin of the frond often forming an exterior valve. 



3. Dicksonia. — Sori terminal on the veins ; involucres cup-shaped or bilabiate. 



4. Darallia. — Sori terminal on the veins; in volueres scale-like or pocket-shaped. 



5. Cystopteris. — Sori on the back of the veius; involucres scale-like or hood-shaped. 



Genus III. Dicksonia, L'Herit.* 



Sori marginal, globose or nearly so, on the summits of the veins ; involucres interior, cup-shaped 

 or bilabiate, the inner value special, the outer formed of modified crenules of the margin, opening 

 exteriorly, the lips closed or overlapping itt firs". ; veins free, forked ; fronds decompound. 



Where this and the next genus meet the line of distinction is not very clear, the border plants 

 fitting as appropriately into one genus as the other. All the local species have decompound, and, as a 

 rule, large fronds. 



a. Sori small, in axillary crenules of the final 'obes ; involucres cup-shaped, or sub-bilabiate, reflexed. 



1 D. cicutaria, Swartz. 



2 D. dissecta, Swaitz. 



3 D. rubiuinosa, Kaulf. 



aa. Sori small, terminal, or in axillary crenules of the final lobes ; involucres fla% as wide or wider 

 than the leaf-segment. 



4. D. anthriscifolia, Kaulf. 



5. D. antillense, Jtnm. 



aaa. Sori large, terminal on the final lubes ; involucres bivalved, the outer hooded and overlapping 

 the inner. 



6. D. couiifolia, Hook. 



aaaa. Sori serial ai\<uud the margins; va.ves of tie involucres closed at first ; many or all of the 

 veinlets fertile. 



7. D. Plumieri, Hook. 



8. D. adiantoides, II. B K. 



1. D. cicutaria, Swaitz. 



Rootstock free-creeping, rusty ciliate ; stipites 3-1 ft. 1. channeled, dark-brown, glossy; fronds 

 quadri-piunate and again pinnatifid, 3£ — 5 ft. 1. ueaily as w. at the base, charfaceous, glossy dark green, 

 glabrous or beneath very . slightly ciliate; pinnae alternate, 1^ — 2-J ft. 1. 10-- 15 in. w., petioTate, the 

 basal ones generally the largest; pinnulao alternate, serrate and finely acuminate at the point, stipitate, 4 

 — 7 in. 1. 1 — 2 in. w. tertiary segments \ — \\ in. 1. \ — \ in. w. rounded and toothed at the apex, within 

 this deeply cut into 4 — 6 lobes to a side, the larger of which are again toothed, the largest of all being 

 on the superior base and 1 — 3 li. 1. by 1 — 2 li. br. ; veins forked ; sori on a crenature in the sinuses of 

 the lobes, one to each, or two or more to the largest - basal lobe ; involucres deep, cup-shaped, \ — \ li. w. 

 sharply reflexed. Plum. Fil. t. 31. 



Var.'i). apiifolia, Hooker — surfaces more naked and brighter; teeth of the margins deeper and 

 sharper; involucres deeper and smaller. Hook., Sp. Fil. vol. 1. t. 20, C. D. incisa, Fee, Fil. Ant. t. 

 25, fig. 1. 



Common in open and lightly shadeJ places from 2.0GV) - 5,000 ft alt., easily recognised from the 

 rest by its bright colour. There aie three or four local forms, which differ most in the size and cutting 

 of the segments and size of the involucres, the var. apiifolia is about the minimum dimensions given above 

 and is easily recognised by its naked very glo>sy surfaces, and deep, sharp, marginal teeth. The form 

 with largest, and bluntly lobei segments occuis at the higher elevations. 



2. D. dissecta, Swartz. 



Rootstock f rtt-^reeping, dull, puberulous ; stipites 1^ — 3 or 4 ft. 1. channeled down the face and 

 laterally, dirty dark coloured; fronds 3£ — 5 ft. I , 3 — 4 it. w., naked dull cloudy green, thin but firm, 

 quadri- pinnate aud again pinnatifid; pinnae neatly or quite opposite, 1| — 2J ft. 1., ^ — 1 ft. w. sessile : 

 pinnulae numerous, 4 — 8 in. 1, 1 — 2 in. w. sessile, the point acuminate and serrate; tertiary segments, 

 approximate, \ — 1^ in. 1 , 2 — 5 li. br,, rounded or blunted at the obtusely, rarely acutely, dentate, open, 

 deeply pinnatifid, the lobes oblong and 3 — 7 to a side, the lowest on the superior side largest and \\ — 3 

 li. 1., by 1 — 1^ li. w., those above half the size, even-m irgiued or their outer part, faintly dentate : veins 

 forked ; sori one to each lobe in a crenature near the base, the larger basal lobe having two or more ; 

 involucres shallow, cup-shaped, or at first two-lipped, the inner valve being at length concealed under 

 the expanded rotund sorus. Plum, Fil. t 30. 2). adiantoides. w., D. cicutarioides, Fee. Fil Ant. t. 2., 



Common in forests from 2,000 to over 6,000 ft. alt. always in damp dripping situations. Mature 

 plants, especially at the higher elevations, bear bulbils in the axils of pinnae. Near the preceding, and 

 presenting as many forms, but distinguished by the sessile pinnae, dull cloudy colour, as a rule blunter 

 segments, and more shallow involucres. One of the forms from the higher elevations has minute sori, 

 and is as finely cut as the var. apiifolia, of the preceding species, the pinnae of which look like lace- work 

 when mounted on paper. 



3. D. rubiginosa, Kaulf. 



Rootstock wide-creeping; stipites scattered, 2 - 3 or more ft. 1. slightly asperous faintly channeled, 

 glabrescent ; fronds 3 — 4 ft. 1. 2$ — 3 ft. w. quadripinnate and again pinnatifid, light green, chartaceous, 

 more or less ciliate ; pinnae 1$ — If ft. 1. 6 — 10 in. w. alternate, nearly sessile ; pinnulae numerous, 

 approximate or close, nearly sessile, serrate- acuminate, 3 — 5 in. 1. J — 14; in. w. — tertiary segments close, 

 blunt or rounded and toothed at the end, 4 — 8 li. 1. 2 — 4 li. w. deeply cut '.into blunt crenate-deutate 



