96 THE WOODSIAS. 
but further south it appears to be half evergreen. 
Among its common names are oblong Woodsia, hairy 
Woodsia and hair fern. A living plant of this species is 
illustrated in the initial design for this chapter. 
The Obtuse Woodsia. 
The obtuse Woodsia (IVoodsta obtusa) is the only com- 
mon member of the genus in eastern North America. 
It is to be looked for on shaded ledges and in the loose 
talus at the base of cliffs and seldom occurs in the ex- 
posed situations affected by //vensis. When it does find 
itself in the sun, the change is apparent at once since it 
takes on a yellow-green colour and becomes thicker and 
more erect. 
In length the blades vary from six to fifteen inches. 
They are oblong ovate in outline and once pinnate with 
triangular-ovate, rather distant pinnae. The pinnz are 
pinnatifid, or pinnate near the base, with oblong, slightly 
lobed pinnules and segments. Both pinnules and pinne 
are quite blunt. This feature is one of the points by 
which it may be distinguished su- 
perficially from Cystopterts fra- 
gilis with which it is very often 
confused. The stipes are about a 
third as long as the blades, light 
in colour and bear scattered 
brownish -scales. Similar scales 
are found on the rachis. The 
* blades are nearly always minutely 
glandular-hairy and the rootstock is short. 
The sori are round and borne near the edge of the 
segments on ordinary fronds. Under a lens they are 
among the most beautiful of their kind. As inall the 
FRUITING PINNA. 
