Part 7

Growing on old bark, wood, mosses, etc. The stipe 1-2 mm. in length, the capillitium elongated 2-4 mm. The commonest of the species, conspicuous by reason of its bright red color.

2. ARCYRIA MINOR, Schw. Sporangium ovoid-oblong; the calyculus small, sulcate and ribbed, granulose. Stipe short, erect, brownish-red in color, standing on a thin hypothallus. Capillitium much elongated after dehiscence, oblong to cylindric, lax and prostrate, bright red to brownish in color; the threads uniform in thickness, 2.5-3 mic., the surface with a series of prominent half-rings, which wind around the thread in a long spiral. Spores globose, even, 7-9 mic. in diameter. See Plate I, Fig. 17.

Growing on old wood, bark, Polyporus, etc. The stipe .4-.7 mm. in length, the capillitium elongated 1.5-3 mm. Not uncommon, but it is usually referred to A. adnata.

3. ARCYRIA ADNATA, Batsch. Sporangium ovoid; the calyculus very small, finely ribbed and granulose. Stipe very short or entirely wanting. Capillitium much expanded after dehiscence, globose or obovoid, pale red to brownish in color; the threads uniform in thickness, about 4 mic., the surface with a series of prominent half-rings with mingled warts and spines, which wind around the thread in a long spiral. Spores globose, even, 6-8 mic. in diameter.

Growing in small clusters on old wood. A small species, the capillitium expanded 1-2 mm., the stipe extremely short, or altogether absent.

4. ARCYRIA NUTANS, Bull. Sporangium cylindric; the calyculus small, granulose, ribbed and sulcate. Stipe very short, arising from a common hypothallus. Capillitium greatly elongated after dehiscence, cylindric, drooping and pendulous, pale yellow or pale ochraceous; the threads 3-4 mic. in thickness, the surface covered with spinules, among which are rings and half-rings, with an indistinct spiral arrangement. Spores globose, even, 7-9 mic. in diameter.

Growing on old wood. The capillitium elongated 4-8 mm., the stipe very short. A very conspicuous species by reason of its long pale yellow capillitium.

§2. PLECTANELLA. Capillitium erect, firmly attached by numerous threads, which issue from the interior of the stipe, but are connate with the wall of the calyculus, after dehiscence not much expanded: the meshes at the surface of the network much smaller than those within, folded back and forth, narrow and irregular, their threads densely warted or spinulose; the meshes of the interior much larger, open and expanded, their threads with minute scattered warts or perfectly smooth.

5. ARCYRIA CINEREA, Bull. Sporangium ovoid or oblong-ovoid; the calyculus very small. Stipe long, erect, cinereous, becoming blackish, standing on a thin hypothallus. Capillitium not much expanded after dehiscence, ovoid-oblong, erect, pale cinereous, sometimes pale yellowish; the external threads densely spinulose, 2-3 mic. in thickness; the threads of the interior thicker, 3-5 mic., and very minutely warted or quite smooth. Spores globose, even, 6-8 mic. in diameter.

Growing on old wood. Capillitium 1-2 mm. long, the stipe about the same length.

6. ARCYRIA COOKEI, Mass. Sporangium ovoid-cylindric, the calyculus very small. Stipe long, erect, gray to mouse-color, darker below, arising from a thin hypothallus. Capillitium not much expanded after dehiscence, ovoid-cylindric, erect, gray to mouse-color; the superficial threads densely and uniformly covered with minute warts, 3-5 mic. in thickness; the threads of the interior thinner, about 2 mic. and smooth, or with very minute scattered warts. Spores globose, even, 6-8 mic. in diameter. See Plate I, Fig. 16.

Growing on old wood, mosses, etc. Capillitium 1-2 mm. long, the stipe about the same length. It seems as common as Arcyria cinerea, and has heretofore been included in it. See Massee's Monograph, p. 154.

7. ARCYRIA DIGITATA, Schw. Sporangium cylindric, the calyculus very small. Stipe long, ascending, brownish in color, usually several fasciculate or to some extent connate, the sporangia divergent at the apex. Capillitium not much expanded after dehiscence, cylindric, pale cinereous, or pale yellowish; the threads variable in thickness. 2-4 mic., those at the surface densely and minutely warted, those of the interior nearly smooth. Spores globose, even, 6-8 mic. in diameter.

Growing on old wood. Capillitium 2-4 mm. long, the stipe about the same length. Arcyria bicolor, B. & C.

III. HETEROTRICHIA, Massee. Sporangia regular, oblong-ovoid, stipitate; the wall a thin delicate membrane, the upper part disappearing at maturity, leaving the basal portion as a small calyculus. Stipe filled with large thick-walled vesicles, which are sub-angular from mutual pressure; these become smaller upward, and pass gradually into normal spores. Capillitium issuing from the interior of the stipe, the central and superficial threads dissimilar, forming a complicated network, with numerous free extremities, the surface minutely warted, or with annular ridges. Spores globose, brownish.

Distinguished from Arcyria by the numerous free extremities of the peripheral portion of the network.

1. HETEROTRICHIA GABRIELLÆ, Massee. Sporangium oblong-ovoid, stipitate; the calyculus small, thin, smooth. Stipe very short, erect, yellowish-brown in color. Capillitium much elongated after dehiscence, cylindric-ovoid, sub-erect; the threads of the central portion about 1.5 mic. thick, with slightly elevated ridges partly encircling the tube, nearly colorless; threads of the peripheral portion bright yellow, 5-6 mic. thick, with numerous short acute free branches, the surface densely and minutely warted. Spores in mass, yellowish-brown, globose, even, 7-8 mic. in diameter. See Plate I, Fig. 18.

Growing on wood; S. Carolina, H. W. Ravenel. The sporangia densely crowded, becoming scattered toward the margin of the cluster. Massee's Monograph of the Myxogasters.

ORDER V. TRICHIACEÆ.

Sporangium regular and stipitate or sessile, rarely plasmodiocarp; the wall a thin membrane, usually granular or venulose on the inner surface, colored as the spores and capillitium, irregularly dehiscent. Capillitium of slender tubules, simple or branched, scarcely forming an evident network; the surface of the threads furnished with continuous ridges, which wind around the tube in a spiral manner. Spores globose, red, brown, yellow, olivaceous.

This order is readily recognized by the spiral ridges which wind around the tubules of the capillitium.

TABLE OF GENERA OF TRICHIACEÆ.

1. HEMIARCYRIA. Capillitium of long slender tubules, arising from the base of the sporangium, or issuing from the interior of the stipe; the spiral ridges parallel and conspicuous.

2. CALONEMA. Capillitium of slender tubules, arising from the base of the sporangium; the surface traversed by a system of branching veins.

3. TRICHIA. Capillitium consisting of numerous short slender tubules, called elaters, which are wholly free; the spiral ridges parallel and conspicuous.

4. OLIGONEMA. Capillitium scanty, composed of elaters habitually irregular and abnormal; the surface variously marked.

I. HEMIARCYRIA, Fr. Sporangia regular and stipitate, rarely plasmodiocarp, the wall at maturity breaking away from above downward, leaving more or less of the lower portion persistent. Stipe more or less elongated, rarely wanting, resting on a thin hypothallus. Capillitium of long slender tubules, more or less branched, arising from the base of the sporangium, or issuing from the interior of the stipe; the spiral ridges parallel and conspicuous, 3-5, rarely more in number, smooth or spinulose. Spores globose, red, yellow.

The genus is related on the one hand to Arcyria by the mode of attachment of the threads, on the other hand to Trichia, by the parallel spiral ridges which wind around them. By the mode of branching of the threads, the species fall readily into two sections.