This family, like the following, has hemiangiocarpic ascocarps
(_apothecia_). These are closed in the early stages, but when ripe
_open_ in a _valvular manner_ by a _longitudinal fissure_; they
are black, oblong, and often twisted. Some species are parasites,
especially upon the Coniferæ.
[Illustration: FIG. 123.--_Lophodermium (Hypoderma)
nervisequium_: _a_ two leaves of _Abies alba_ seen from above
with pycnidia; _b_ a leaf seen from the underside with apothecia;
_c_ an ascus with ascospores. (× 500.)]
[Illustration: FIG. 124.--Three leaves of the Red-pine with
_Lophodermium macrosporum_: _a_ under side of the leaves with
apothecia; _b_ a leaf from upper side with pycnidia. (× about 2.)]
[Illustration: FIG. 125.--_Lophodermium pinastri_: _a_ leaves of
_Pinus sylvestris_ with apothecia (nat. size); _b_ two paraphyses
and an ascus with filamentous spores.]
Order 1. =Hysteriaceæ.= _Hysterium pulicare_ upon the ruptured bark of
many trees.
Order 2. =Hypodermaceæ.= The species of _Lophodermium_ live upon the
leaves of Conifers, and are the cause of their falling off (_blight_).
_L. pinastri_ (Fig. 125), on the leaves of _Pinus_ and _Picea_; the
leaves become red-brown and fall off; at first conidiocarps are formed,
and later apothecia; _L. nervisequium_ (Fig. 123), on _Abies alba_;
_L. macrosporum_ (Fig. 124), on _Picea excelsa_; _L. brachysporum_, on
_Pinus strobus_.