nS 21. ADIAKTUM, § EUADIANTUM, 



18. A. trapeziforim, L. ; st. 6-12 in. 1., firm, erect, naked, polislied, blackish ; 

 //-. with a central pinna 4-8. in. 1., 2-3 in. br., and 2 to 4 large spreading ones on 



each side, the lowest of which are often ];ranched again ; segm. 1-^2 in. 1., 

 |-| in. br., dimidiate, the sides nearly parallel, the outer edge oblique, both it 

 and the upper one bluntly, not deeply iobed, the lowest on stalks j-| in. 1. ; texture 

 papyraceo-herbaceous ; rachis and both surfaces naked ; sori numerous, con- 

 tiguous, transversely oblong, placed round the upper and outer edge. — Hfc. Sp. 2. 

 2^. 33. Hk. £• Gr. t. 98. — /3, A. pentadactyJon, L. & F. ; lower margin of the 

 segments somewliat decurved obliquely from the petiole. — y, A. cultratum, 

 J. Sm. ; outer edge of the segment bluntly rounded. — Hk. Sp. 2. p. 34. 



Hab. Tropical America, from Mexico and the West Indies southward to Brazil. — A 

 well-known plant, readily distinguished from its neighbours by its ample trapezoid seg- 

 ments. A. Cathennm of the gardens appears not to ditFer materially. 



19. A. polt/phyllum, Willd. ; st. 12-18 in. I., strong, erect, blackish, polished, 

 rather scabrous; fr. 2-3 ft. I., 12-18 in. br., the upper part simply pinnate; 

 lower pinnce sometimes 1 ft. 1., 6 in. br., with a long terminal and numerous 

 erecto-patent lateral pinnules; segm. |-1 in. 1., j in. deep, dimidiate, the upper 

 and lower edge nearly parallel, the point bluntly rounded, the upper edge 

 sharply but not deeply toothed ; texture coriaceous, veins prominent ; rachis and 

 surfaces naked ; sori in numerous suborbicular patches placed in hollows in lobes 

 along the upper edge. — Hk. Sp. 2. p. 49. A. cardiochlaena, Kunze, Hk. Sp. 2. 

 p. 50. t. 83. A. A. ]\Iatthewsianum, Hk. Sp. 2. p. 35. t. 84. A. A. macro- 

 cladum, Klotzsch, Hk. Sp>. 2. p. 49. t. 83. B. 



Hab. Columbia and Peru. — A large copiously-branched plant, with very numerous 

 (sometimes fifty to a pinna) closely-placed subsessile segments. A. tomentosum, Klotzsch 

 (A. Klotzachianum, Hk.), and A. urophyllum, Hk., seem forms of this with slightly- 

 pubescent rachises. 



20. A. glaucescens, Klotzsch ; st. G-9 in. 1., slender, erect, naked, polished ; 

 fr. 1 ft. each way, with a terminal pinna and several loosely-spreading ones on 

 each side ; pinnl. |-1 in. 1., j-g in. deep, dimidiate, the lower border nearly 

 straight, the upper nearly parallel with it, almost entire, the outer margin 

 bluntly rounded, the lowest on short stalks ; texture pajiyraceo-herbaceous ; 

 rachises naked, under surface glaucous ; soi'i in numerous patches, 1-1^ lin. 

 br., with a s])ace between them, placed round the upper and outer edge. — 

 Hk. Sp. 2. p. 26. 



Hab. Ecuador, Guiana, and north of Brazil. — Perhaps this also is not distinct from 

 A. polyphylium, but it is less cojjiously branched, and the segments are fewer and thinner 

 in texture. 



*'''* Ultimate segments dimidiate, the stems pubescent. Sp. 21-31. 



21. A. Henshvianum, Hk. fil. ; st. 6-12 in. 1., erect, dark chesnut-brown, naked, 

 glossy ; fr. 12-18 in. 1., 6-9 in. br., ovate tripinnate, furnished with numerous 

 diatant pinnce on each side, the upper of which are simple, but the lowest slightly 

 branched ; segm. ^-| in. br,, J-| in. deep, dimidiate, the lower line nearly straight, 

 the upper rather rounded, a good deal Iobed, the point bluntly rounded ; texture 

 papyraceo-lierbaceous ; rachis and under surface hairy; sori obversely reniforin, 

 placed in the hollows of the lobes of the upper and outer edge. — Hk. Sp. 2. p. 43. 

 A. sessilifolium, Hk. p. 44. A. Reichenbachii, Moritz, A. Isetum, Mett. 



Hab. Columbia, Peru, Galapagos group. — This is well-marked amongst its neighbours 

 by the shape of its segments, the inner edge of which is often inibricatod over the rachis, 

 as in .4. Shepherdi and concinnum, and by the reniform sori which encircle a very distinct 

 hollow. 



22. A. cristatum, L. ; st. 6-12 in. 1., strong, erect, tomentose ; fr. 1^-3 ft., 1. 



