ADIANTUM. 21 



(he pinnules close-placed, rather chartaceous than membranaceous, large 

 (for this group), very obtuse, in shape, if I may so express myself, almost a 

 four-sided parallelogram, but with a downward curvature (deorsum falcatse) : 

 the sori moderately large, oval-oblong, close-placed, very regular, often ex- 

 tending round the apex, and from 9 to 12 or 13 on a pinna. — A still smaller 

 state of this plant, as I am disposed to consider it, is the A. Sckoinhurgkia- 

 num, Klotzsch in Herb. J. Sm. n. 1184, from British Guiana. 



42. A. Klotzscliinmim, Hook. ; large, fronds bipinnate, 

 pinnaj lanceolate shortly acuminate, pinnules diraidiato-ob- 

 long obtuse submembranaceous dark green (almost an oblique 

 parallelogram) deorsely subfalcate, very obscurely crenate 

 truncate at the uj)per base, the small blunt teeth soriferous, 

 involucres exceedingly numerous oblong-reniform or semi-or- 

 bicular approximate very regular 17 to 24, rachis slender 

 compressed downy on the upper side dark purple shining and 

 glabrous beneath, stipes long erect stout ebeneous with a faint 

 line of hairs on one side, caudex creeping stout. (Tab. 

 LXXXII. C.) A. tomentosum, Klotzsch, in LiinKBa, xviii. p. 

 553. Kze. in Linncea, 1848, p. 224. A. Brasiliense ? Hook. 

 in Sprnce, Herb. Amaz. w. 51. A. politum, ./. Sm. in Hook. 

 Lond. Joiirn. of Bot. i. p. 198 [not Humb.) 



Hab. British Guiana, Rich. Schomburffk, n. 1202, Klotzsch, in Herb. 

 J. Smith). Sir R. Schomburgk, n. 349 (in Herb. J. Sm. and Hook., from 

 the Berbice). Surinam, Keppler, n. 1773, c. (Kunze). — This I consider 

 a very good, and it assuredly is a very fine species and worthy of bearing 

 Dr. Klotzsch's name, to which, by the right of priority, indeed, it is by no 

 means entitled ; but the appellation A. tomentosum is quite inajiplicable to 

 a plant which has no further approach to touieutum than a delicate down 

 or pubescence on the upper surface of the compressed rachis; whereas the 

 preceding species, next to which Dr. Klotzsch has justly placed it, and its 

 closest ally, A. Cayennense, Kl., have the rachis all over, and the stipes too, 

 densely /msco- (paleaceo) tomentose. So that till I read the descriptions 

 more carefully I imagined that the authentic names of the specimens 

 in Mr. J. Smith's Herbarium had been transposed. Kunze, however, in 

 the ' Linnaea,' 1. c, strangely separates these two plants, <kc., placing be- 

 tween them A. villosiim (a monosoroiis species, if the true plant is intended, 

 whereas the sori are, here, according to Klotzsch, 18 — 22 on a pinnule), 

 iiuA A.paclujsnrum (the same as A. prionophyllum, according to Presl) ; 

 and Kunze further says, " Distinctissima species. Rhizoma illi Ad. Cayen- 

 nenfis simile, phyllopodia breviora, alterna, magis remota, ferrugineo-pale- 

 acea, radiculae frequentiores. Stipites basi non adscendentes, sed stricti, 

 sparsim ferrugineo-paleacei.'' Mr. Spruce's specimen, which is perfect, 

 corresponds precisely with Dr. Klotzsch's. Both have the decurvo-falcate 

 |iinnules very crowded ; but the sori and rachis are quite different. 



43. A. prionop/ii/lluni, H. B. K. ; often large (1 — 2 feet 

 and more), frond rather compact bipinnate, pinnae 5 — 11 

 lateral ones horizontal terminal one elongated all commonly 

 caudate at the extremity, pinnules ajiproximate so as gene- 



