6o 
THE FERNS OF SOUTH AFRICA 
Genus i. Trichomanes. Involucre a deep cup, not much 
compressed, and with an entire mouth, or slightly 
two-lipped when young. 
Genus 2. Hymenophyllum. Involucre a cup of same 
texture as the frond, and placed on its margin, 
more or less compressed, and distinctly two-lipped, 
or cut into two valves. 
Sub-Order II. Cyatheaceae. Tree-ferns. Trunk arborescent 
and woody. Sori globose or shortly conical, situated 
on the back of the frond, and contained in a cup- 
like or more or less imperfect involucre. Capsules 
sessile or nearly so, and having a broad nearly 
vertical ring. 
Genus 3. Cyathea. Involucre at first completely enclosing 
the sorus, afterwards bursting at the top, and 
remaining as a cup under and around the capsules, 
which surround a raised receptacle. Stem tree-like. 
Genus 4. Hemitelia. Involucre only a scale placed under 
the capsules which surround a raised receptacle. 
Involucre sometimes absent. Stem tree-like. 
Sub-Order III. Polypodiaceae. Habit various. Capsules many 
in a sorus, small, often stalked, having a jointed 
elastic band passing up one side, over the top, and 
partly down the other side, and opening horizontally 
at the part where the band is absent. Sori on the 
back of the frond, with or without indusia. 
* Woodsieae. Sori scattered on the back of the frond; in- 
volucre cup-like or scale-like, inferior, and enclosing 
or folding over the sorus. 
Genus 5. Woodsia. Involucre cup-like, at first enclosing 
the sorus, afterwards bursting at the top into 
several lobes. Plant small, herbaceous. 
Genus 6. Cystopteris. Involucre like a scale attached 
under the sorus by its wide end, and at first having 
the other end turned hood-like over the sorus. 
** Aspidieae. Fronds not articulated to the rhizome; sori 
roundish, placed on the back of the frond, not 
marginal ; indusium usually present and reniform 
or peltate, absent in some species. 
Genus 7. Dryopteris. Sori kidney-shaped or elongated, 
indusium kidney-shaped, attached by its sinus, 
absent in some species. Pinnae not articulated. 
