Peck CH. 1896. New Species of Fungi. Bulletin of the Torrey Botanical Club 23: 419.
TYLOSTOMA PUNCTATUM.
Peridium subglobose, flattened and umbilicate at the base, the external peridium falling away above, persistent at the base, the internal peridium papery but rather firm and tough, minutely and irregularly punctate-pitted, whitish, the mouth slightly prominent, small, lacerated ; stem cylindrical, obscurely squamose or rimose-squamose, sulcate-striate above, hollow, subferruginous, white within; spores pale-ferruginous, globose, minutely warted or roughened, .00016 to .0002 in. broad, the threads of the capillitium hyaline, sparsely branched, .0003 to .0004 in, broad, broader than the spores, the ends obtuse or subtruncate, occasionally thickened; spores globose, .00016 to .0002 in. broad; plant 1 to 1.5 in. high, peridium 5 to 6 lines in diameter; stem about 2 lines thick.
Sandy ground in pastures. Kansas. July. Bartholomew.
The peculiar character of the species is in the minute punctate pits or impressions in the inner peridium. These are somewhat scattered and unequal and are similar to those seen in the seed coat of some species of Lithospermum. I find no mention of such character in any of the published species.
Etym.: the name refers to the punctate or areolate nature of the endoperidium.
Spore-sac relatively small-sized, up to 12 mm diam. Exoperidium hyphal, with threads mingled with sand grains, which slowly wears off excepting as a small band at the base. Endoperidium whitish to cinereous, never truly smooth but rather pitted from the scars of the sand grains. Mouth fimbriate, without a peristome, not noticeably mammose; in mature specimens it hardens and tends to appear almost tubular. Socket appressed, inconspicuous, with a membrane lacerated in unequal squamules. Gleba ochraceous-ferrugineous. Stem up to 30 x 3 mm, reddish brown or darker, decorticating and leaving a lighter surface, fistulose, subwoody, with conspicuous silky threads in the medulla.
Spores coloured, subglobose to ellipsoid, minutely verrucose, some only asperulate under L.M., most apiculate, some almost smooth, 4-5.4 x 5.4-6.1 µm. Under SEM the ornamentation appears formed by relatively large and low verrucae, some anastomosed in crests. Capillitium slightly coloured, branched and septate; threads thick-walled, with prominences, lumen wavy, somewhat swollen at the coloured septa, 3.3-8.1 µm diam.
Habitat: sandy soils in pastures.
Distribution: North America: it seems to be confined to the Great Lakes region of the United States and Canada.
Lectotype (selected): United States, Kansas, Rooks Co., leg. E. Bartholomew, 23.VII.1896 (MO 5630 at BPI!). Probably all the remaining materials marked "Type" at CU and S are isotypes. Unfortunately the original type collection contained mixed elements for which reason the former has been selected as lectotype. Furthermore, the situation becomes complicated by the existence of several other collections from the same site, all marked "Type".