8 GLEICHENIA, 



Hook. Ic. PL r. i. /. 92. Mertensia simplex, Desih MS. in 

 Did. des Sc. Nat. wilh ajigure. 



Hab. Andes of Quito, Prof. W. Jameson {n. 83), Cordillera of Peru, Ma- 

 thews (n. 1093). — A simple-fronded fern, in the adult state, is certainly a 

 phenomenon in the genus Gleichcnia, and 1 have more than once, espe- 

 cially on finding a specimen proliferous at the apex, with circinate infant 

 hranches, been disposed to consider it a state of the preceding species; I 

 can hardly say the infant state, because there is generally fructification in 

 abundance. 13ut on again directing atteniion to the subject, I am induced 

 to keep them distinct: — for I find that copious specimens of both plants 

 are very constant to their characters : and though I have received, at seve- 

 ral different periods, from Professor Jameson, the respective plants, they 

 arc unifomily the same; and by my correspondent sending the two with 

 different numbers, he appears not to entertain the sliadow of a doubt of 

 their being distinct. Of the present I may observe that 1 never find the 

 stipes otlierwise than free from chaffy scales : the scales on the rachis are 

 of a much paler colour than in the preceding, the frond is broader, the seg- 

 ments longer and narrower, the lower ones often rather remotely separated 

 from one another, the apex, when completely developed, caudate. 



23. G. (Mertensia) pubescens,Wi\\d.; stipes round glabrous 

 or more or less chaffy, fronds repeatedly dichotomous leafy, 

 branches or ]iinnai lanceolate acuminate ascending pinnatifid, 

 segments horizontal or nearly so linear obtuse or retuse, be- 

 neath clothed with a dense pale ferruginous cobwebby sub- 

 stance in which the sori are immersed, capsules 4 — 5. — Mer- 

 tensia ferruginca, De.sr. — M.immersa, Kaulf. — Hook.et Grev. 

 Ic.Fil. t 15. M. velata, A'^e.- M. bifida, JVillcL— 13. glabra ; 

 fronds more or less glabrous beneath. M. furcata, Sw.^ Acros- 

 tichum furcalum, L. — Polypodium, Sw. Fl. Ind. Occ. — Plum. 

 Fit. t. 28. — y. pinna; or branches narrow. 



Hab. Brazil and West Indian islands, frequent. Peru, Poppiy and Herb, 

 nostr. Guatemala, Mr. Skinner, and Rio, Mr. Gardner, (larger and bright 

 green in drying). — /3. West Indies, Sivartz. South Brazil, Sellow, Tivee- 

 tiie. — y. Guiana, Schombtm/k, n. 1039. — A very frequent fern in the tropi- 

 cal })arts of the New World, and, as far as I know, confined to the New 

 World ; growing at various elevations and in various exposures, and con- 

 s(!quently presenting different appearances. I cannot but thii>k that the 

 Mertensia furcata, Sw., is merely a glabrous or nearly glabrous variety of 

 G. jmbescens ; but I prefer retaining the latter name as the more charac- 

 teristic of the perfect state of the plant, which is remarkai^le for the cob- 

 webby like wool which clothes the whole underside of the frond with a pale 

 ferruginous substance. Martins indeed says, " it is distinguished from M. 

 furcata and others by the more patulous branches, by denser and more per- 

 sistent down, by fewer lacinia; less pectinalcdly disposed and decurrent on 

 one side the lower petioles or branches:" — but all tliese, as is evident from 

 the very numerous specimens before me, are very variable characters. It 

 seems to be a large species, and the copious dichotomies very leafy. — I 

 regret that I have not the figure referred to by Willdeuow for his M. bifi- 

 da ; Act. Holm, 1804, t.5. f . B : a species taken up by all authors, but which 

 from the description I should scarcely think different from G. jmbescens, 

 next to which it is placed. 



