SPECULATIONS.
The scanty knowledge we have of the real structure of this group of plants leaves much to speculation. They are all evidently closely related plants, and I think best classified under one general head, or genus, Camillea. They are quite different from the Hypoxylons of the temperate region, although we do not question that the tropical species are included in Saccardo mostly under Hypoxylon. When we come to compare what little we know of the species we find several differences on which "genera" could be based, and no doubt will be in time. In the original sense, Camillea might be restricted to the two cylindrical species, C. Leprieurii and C. Bacillum.
Then we have the short, cylindrical or globose forms with persistent or semi-persistent perithecia, Camillea Labellum, C. Cyclops and C. turbinata with the intermediate species C. mucronata. The above will form one, or two, genera, according to taste.
In the following plants we find no perithecia in the ripe specimens, hence of course they will in time be considered a genus. We believe there are two distinct differences between the few species we know, corresponding with the old ideas of Bovista and Lycoperdon in the puff balls. Camillea Sagraena and C. poculiformis, with two divisions of the gleba, a fertile and a sterile portion, and Camillea Bomba and C. globosa (?) with homogenous gleba. The species Camillea Sagraena differs from the other in having the fertile portion composed largely of spores (scanty in others) and in having part of the sterile portion of uncolored hyphae. Of course, it will form a "genus." Thus the genus Camillea can be easily divided into five "genera" and we make the suggestion for the benefit of those engaged in breaking up the old genera, and proposing new names to which to add their own. Who will rise to the occasion?
THE GENUS THAMNOMYCES.
This is included in Saccardo as part of Xylaria, but we feel is well entitled to generic rank. It was proposed by Ehrenberg in 1820 for a curious species collected in Brazil. The genus differs from Xylaria in having the fruiting bodies on the ends of branches, which in one species are dichotomous, or in the other two species sessile or subsessile and borne on a slender rhachis. There are conflicting accounts of the structure of these bodies. The original, by Ehrenberg, represents them as hollow bodies, with the perithecia imbedded in the walls. That also is as shown by Cooke and is the usual idea. Moeller, on the contrary, represents each body as a perithecium, and our examination confirms Moeller's view. If Moeller's account is true, as it seems to be, it is a strong reason why Thamnomyces should not be classed with Xylaria.
The usual Xylaria has a white, sterile, central portion known as the stroma, bearing a carbonous crust. The perithecia are generally imbedded in the outer portion of the stroma, the mouths opening through the carbonous crust. The walls of the perithecia are carbonous, and confluent with the crust. The genus Thamnomyces has a slender stem, entirely carbonous. This seems to have been the main difference between it and Xylaria in the old classification, but the character is fallacious.
There are Species of Xylaria that have no white stroma. The stem is slender and carbonous and bears the carbonous fruit bodies, superficial, but sessile and globose. Fries proposed for these species, the generic name Rhizomorpha, which Saccardo united with Thamnomyces as a section of Xylaria. In my view it is an entirely different idea from Thamnomyces and should form a section in itself in the genus Xylaria. There are Several species like Xylaria scopiformis that intimately connect Rhizomorpha with Xylaria.
We believe the genus Thamnomyces, in the true sense, embraces only three species as follows: