Trichomanes radicans 
By ELizABETH G, BRITTON 
Having come to the conclusion that Poterophora Donnellii Wolle, 
originally described as a fresh-water alga, is a filamentous prothal- 
lium of a species of Zrichomanes, collected on trunks of trees in 
Florida by J. Donnell Smith, we have been somewhat surprised 
to learn that the only record for any species of this genus in 
Florida is a doubtful one. Chapman, in all three editions of his 
Southern Flora, states that 7: Petersii had been sent to him among 
mosses from Pensacola, Florida, without stating the habitat or 
name of collector. As the first leaves of both Vittaria lineata and 
Campyloneuron phyllitidis might readily be mistaken for a small 
species of Zrichomanes, there is some doubt as to whether this 
statement is correct. No specimens occur in Chapman’s original 
herbarium now in the Columbia University collections, and at 
Biltmore no further information can be obtained from Chapman’s 
later herbarium. Meanwhile I have made a curious set of discov- 
eries, and confirmed the opinion held by most students of North 
American ferns that the species known in our text-books as 
Trichomanes radicans is quite distinct from the species originally 
described by Swartz. 
Trichomanes radicans as collected by Swartz was from Jamaica, 
where it grew closely clinging to trees in the forest, and climbed by 
a long tomentose rootstock ; the fronds were sparse, on stipes I-3 
inches long, margined by the decurrent tissue of the leaf, which is 
Ovate-lanceolate, sub-tripinnate, and dark green. The rachis was 
Partially margined. Leaflets patent, alternate ; pinnules alternate, 
Pinnatifid; lobes linear, apex bipartite and obtuse. Urceolate 
fructification subpedicellate, scarcely exserted, the lobes laciniate, 
membranous, cylindric. Columella long setaceous. 
Compared with 7: scandens L., he says it differs in the place 
where it was found, the angular rachis, which is not black; the 
laciniate ends of the lobes not bifid, and the shorter columella. 
__ This comparison raises the question as to what 7. scandens L. 
'S, and here too we find a diversity of opinion, most authors having 
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