7. GLEICHENIA. 57 



§ 3. MERTENSIA. a. Dicranopteris. 



a. Fronds forked; branches pinnate; secondary branches (pinnulae) whether or 

 not branched again, (Diplopterygium, Diels, in Engl. ^ Prantl, Nat. Pfl. 

 Fam., I\i,fig. i88, A). 

 h. Pimmlae not branched. 



e. Pinnulae distant. (3) G. Norrisii. 



c.e. Pinnulae close. 



d. Under surface naked or sparingly scaly. (4) 6. glauca. 



d.d. Under surface densely tomentose with ciliate or fimbriate 



scales. (5) G. arachnoidea 



b,b. Pinnulae dichotomously branched. (6) G. Warburgii. 



UM. Fronds forked; branches dichotomously forked again. 



1. The ultimate branches only leafy. The forkings whether or not purveyed 

 with a pair of deflexed, opposite, leafy, accessory branches, (Acroptery- 

 gium k Heteropterygium, Diels, I. c, fig. i88, C — D). 



(7) G. linearis. 

 l.±. All the branchings leafy like the ultimate ones, but the 1 — 3 lower ones 

 not rarely nudate, (Holopterygium, Diels, I. c, fig. i88, B). 

 9. Ultimate segments (lobes or leaflets) horizontally spreading. 



(8) G. laevigata. 

 9,S, Ultimate segments {lobes or leaflets) more or lessl oblique. 



3. Lobes or leaflets {not the rachises) naked beneath. 

 ^. Toeoturo coriaceous ; Under surface glaucmis. 



(9) G. oceanica. 

 5i<.)tc. Toeoiuro mombranacoouB; Under surface noi glaucous. 



(10) G. flahellata. 

 3.3. Lobes or leaflets hairy, scaly or tomentose beneath, at least 

 on the central ribs when young. 

 S:. Rachises hairy, scaly and white-powdery. 



(11) G. Koordersii. 

 ^.4. Rachises hairy or scaly, but not white-powd&-y. 



S. Lobes or leaflets toothed at the apex. (12) G. hirta. 

 StS. Lobes or leaflets not toothed at the apex. 

 €. Rachises long-hairy beneath. 



(15) G. hispida. 

 0.0. Rachises doasel f- scaly beneath. (14) G. vestita. 



