Fig. 2.23Puffballs (Lycoperdonspp.) in an immature white stage (a) and mature brown stage (b), about 3 cm dia-
meter. These are similar to the earthstars shown in Fig. 2.22, but frequently are attached to woody substrates. Puffballs
produce basidiospores from basidia that develop within the fruitbody. The spores are not shot from the sterigmata but
drop off and accumulate within chambers inside the developing fruitbody. Mature puffballs have a thin, papery outer
casing with a pore at the top. Spores are puffed from the pore by raindrops.(a) (b)(a) (b)Fig. 2.24Two characteristic wood-rotting fungi of Scottish birch woods. (a) Fomes fomentarius(the hoof fungus), about
20 cm diameter. This hard, woody, perennial, bracket fungus is very common. The hyphae growing within the wood
cause a brown rot. The underside of the basidiocarp consists of minute pores through which the basidiospores fall and
are then wind-dispersed. (b) A bracket-shaped polypore of the fungus Piptoporus betulinus, the “razor strop” fungus.Fig. 2.25(a) An evanescent bracket of Polyporus squamosus(Dryad’s saddle), about 25 cm diameter, growing on a senes-
cent poplar tree. The spores are released through pores on the underside, but the bracket senesces and decays within
a few months and is usually replaced annually. (b) A large conical-shaped fruitbody of Phaeolus schweinitzii, parasitic
on the roots of conifers. The cap is about 15 cm diameter, cream-colored at the margin but dark brown in the center.
In this fresh specimen the toadstool is covered with a downy felt on the upper surface.(a) (b)FB4eC02 04/20/2005 02:52PM Page 35