62 
THE FERNS OF SOUTH AFRICA 
Genus 19. Asplenium. Sori linear or oblong, placed ob- 
liquely between the midrib and the margin ; in- 
dusium present. 
Genus 20. Ceterach. Sori linear, without true indusium, 
but hidden among closely imbricated brown chaffy 
scales. 
Genus 21. Blechnum. Fronds dimorphous. Sori linear, 
parallel with the midrib, and intramarginal or 
occupying the whole under-surface of the fertile 
pinnae (variable in some species). Indusium 
present. 
Genus 22. Stenochlaena . Fronds dimorphous. Sori oc- 
cupying the whole under-surface of the fertile frond, 
without indusium. 
Pterideae. Sori terminal on the veins or linear on 
the outer veins. Except in Gymnogramminae 
and Notholaena indusium is present, formed of 
the reflexed margin. Sori separate or more or 
less continuous. 
A. Gymnogramminae. Indusium absent ; sori linear on 
the outer veins. 
Genus 23. Anogramma. Plant small, annual. 
Genus 24. Gymnogramma. Veins free ; plant perennial ; 
frond 3-pinnatifid. 
Genus 25. Ceropteris . Under-surface coated with white 
or yellow powder ; frond 4-pinnatifid. 
B. Cheilanthinae. Sori on the frond close to the margin, 
separate or more or less confluent, covered by the 
reflexed margin (except in Notholaena ). 
Genus 26. Pellaea. Indusium continuous or sometimes 
imperfectly continuous, interrupted or roundish. 
Capsules produced on the frond, under the in- 
dusium, in a wide line. 
Genus 27. Doryopteris . Sori as in Pellaea. Fronds small, 
deltoid. 
Genus 28. Adiantopsis. Involucres distinct, roundish, con- 
fined to the apex of a single veinlet. 
Genus 29. Notholaena. Sori marginal, linear; indusium 
absent. 
