Under Xylariaei we have: Stipitate-- Stroma corky, subelavate Xylaria.
Stroma somewhat corky, discoid Poronia.
_Cordyceps. Fr._
Cordyceps is from a Greek word meaning a club and a Latin word meaning a head. It is a genus of Pyrenomycetous fungi of which a few grow upon other fungi, but by far the greater number are parasitic upon insects or their larva, as will be seen in Figure 491.
The spores enter the breathing openings along the sides of the larva and the mycelium grows until it fills the interior of the larva and kills it.
In fructification a stalk rises from the body of the insect or larva and in the enlarged extremity of this the perithecia are grouped. The stroma is vertical and fleshy, head distinct, hyaline or colored; sporidia repeatedly divided and sub-moniliform.
_Cordyceps Herculea._ (_Schw._) _Sacc._
[Ill.u.s.tration: Figure 491.--Cordyceps herculea. Showing the grub upon which this species grows.]
Herculea is so called from its large size. The halftone will readily identify this species. The plant is quite large, clavate in form, the head oblong, round, slightly tapering upward with a decided protuberance at the apex, as will be seen in Figure 491. The head is a light yellow in all specimens I found, not alutaceous as Schw. states, nor is the head obtuse. I found several specimens on a sidehill in Haynes"s Hollow in August and September, all growing from bodies of the large white grubs which are found about rotten wood. They were found during wet weather. They were identified by both Dr. Peck and Dr. Herbst.
_Cordyceps militaris. Fr._
[Ill.u.s.tration: Figure 492.--Cordyceps militaris.]
This is much smaller and more common than C. Herculea.
Conidia--Subcaespitose, white; stem distinct, simple, becoming smooth; clubs incra.s.sated, mealy; Conidia globose. Ascoph.o.r.e--Fleshy, orange-red; head clavate, tuberculose; stem equal; sporidia long, breaking up into joints. This is frequently called Torrubia militaris.
It is known as the caterpillar fungus. Its spores are cylindrical and are produced upon orange-red fruiting bodies in the fall. As soon as the spore falls on the caterpillar it sends out germ-threads which penetrate the caterpillar. Here the threads form long narrow spores which break off and form other spores until the body-cavity is entirely filled. The caterpillar soon becomes sluggish and dies. The fungus continues to grow until it has completely appropriated all of the insect"s soft parts, externally a perfect caterpillar but internally completely filled with mycelial threads. Under favorable conditions this mycelial caterpillar, which has become a storage organ, will send up an orange-red club-shaped body, as will be seen in Figure 492, and will produce the kind of spores described above. Under some conditions this mycelial caterpillar may be made to produce a dense growth of threads from its entire surface, looking like a small white ball, and from these threads another kind of spore is formed. These spores are pinched off in great numbers and will germinate in the larva the same as the sac spore. The specimens were found by Mrs. E. B. Blackford near Boston, and photographed by Dr.
Kellerman.
_Cordyceps capitata. Fr._
[Ill.u.s.tration: _Photo by C. G. Lloyd._
Figure 493.--Cordyceps capitata. Natural size.]
This plant is fleshy, capitate, head ovate, bay-brown, stem yellow, then blackish.
This plant is parasitic on Elaphomyces granulatus. It is shown at the base of the stem of the plant. It grows two or three inches under the surface and somewhat resembles a truffle in appearance.
Both are very interesting plants. The plant in Figure 493 was found near Boston, Ma.s.s. They are usually found in pine woods, often in tufts. The stems are from one to four inches long, nearly equal, smooth, lemon-colored, at length fibroso-strigose and blackish.
It is sometimes called Torrubia capitata.
CHAPTER XVII.
MYXOMYCETES.
The plants under this head belong to the slime-moulds and at first are wholly gelatinous. All the species and genera are small and easily overlooked, yet they are intensely interesting when carefully observed.
In the morning you may see a ma.s.s of gelatinous matter and in the evening a beautiful net work of threads and spores, the transformation being so rapid. This gelatinous ma.s.s is known as protoplasm or plasmodium, and the motive power of the plasmodium has suggested to many that they should be placed in the animal kingdom, or called fungus animals. The same is true of Schizomycetes, to which all the bacteria, bacillus, spirillum, and vibrio, and a number of other groups belong. I have only a few Myxomycetes to present. I have watched the development of a number of plants of this group, but because of the scarcity of literature upon the subject I have been unable to identify them satisfactorily.
_Lycogala epidendrum. Fr._
[Ill.u.s.tration: Figure 494.--Lycogala epidendrum.]
This is called the Stump Lycogala. It is quite common, seeming in a certain stage to be a small puffball. The peridium has a double membrane, papery, persistent, bursting irregularly at the apex; externally minutely warty, nearly round, blood-red or pinkish, then brownish; mouth irregular; spores becoming pale, or violet.
_Reticularia maxima. Fr._
This is quite common on partially decayed logs. The peridium is very thin, tuberculose, effused, delicate, olivaceous-brown; spores olive, echinulate or spiny.
_Didymius xanthopus. Fr._
These are very small yellow-stemmed plants, found on oak leaves in wet weather. The sporangium has an inner membranaceous peridium; the whole is round, brown, whitish. The stem is elongated, even, yellow. The columella is stipitate into the sporangia.
_D. cinereum. Fr._
Sporangia sessile, round, whitish, covered with an ashy-gray scurf.
Spores black. Very small. On fallen oak leaves. Easily overlooked.
_Xylaria. Schrank._
Xylaria means pertaining to wood. It is usually vertical, more or less stipitate. The stroma is between fleshy and corky, covered with a black or rufous bark.
_Xylaria polymorpha. Grev._
[Ill.u.s.tration: Figure 495.--Xylaria polymorpha. Natural size.]
Polymorpha means many forms. It is nearly fleshy, a number usually growing together, or gregarious; thickened as if swollen, irregular; dirty-white, then black; the receptacle bearing perithecia in every part.
This plant is quite common in our woods, growing about old stumps or on decayed sticks or pieces of wood. The spore-openings can be seen with an ordinary hand-gla.s.s.
_Xylaria polymorpha, var. spathularia._
[Ill.u.s.tration: Figure 496.--Xylaria polymorpha var. spathularia. Natural size.]
Spathularia means in the form of a spathula or spatula. It is vertical and stipitate, the stem being more definite than in the X. polymorpha, the stroma being between fleshy and corky, frequently growing in numbers or gregarious, turgid, fairly regular, dirty-white, then brownish-red, finally black. An ordinary hand gla.s.s will show how it bears perithecia in all its parts. This will be clearly seen in the section on the right.