Monographs Details: Astomiopsis saint-pierrei Thér. ex W.R.Buck
Authority: (Ditrichaceae). Bryologist. 80: 359-362.
Family:Ditrichaceae
Description:Latin Diagnosis - Species foliis oblongo-lanceolatis marginibus recurvis, costa percurrente, capsulis immersis, annulo deciduo et calyptris magnis cucullatis a congeneribus diversa.

Species Description - Plants gregarious, golden above, reddish below, minute, 3-4 mm tall with all but 1 mm buried in the soil, mostly forked near the base, the male branch erect, about as tall as the female branch, which appears to be an innovation from themale, each branch with 2-3 previous seasons' inflorescences which are overgrown by subfloral innovations. Leaves lustrous, erect-spreading, scarcely changed when moist, oblong-lanceolate obtuse, commonly subfalcate, concave, 1.03-1.55 mm long, 0.18-0.31 mm wide; margins mostly recurved from the base almost to the apex, entire to subcrenulate; costa percurrent, becoming wider above and filling the acumen; cells ± rectangular, lax and thin-walled below, becoming thicker walled and shorter above, oval to round, mostly 1-2:1, 6-12 µm long, mostly bistratose at apex. Autoicous. Perigonial bracts broadly triangular, 0.50-0.63 mm long, the costa subpercurrent to percurrent, the areolation similar to that of vegetative leaves but laxer. Perichaetial leaves not differentiated; archegonia extremely long-necked, up to 0.7 mm long. Setae short, 0.37-0.44 mm long, pale, straight. Capsules immersed, ellipsoidal, 0.50-0.60 mm long (including the operculum), golden-brown, shiny; exothecial cells short-rectangular, thin-walled; stomata none; annulus of 1-3 rows of thick-walled cells about the same size as the exothecial cells, deciduous, sometimes adhering to the operculum; operculum bluntly conic, pale; peristome none. Spores ± spherical, 22-30 µm diam., proximally scarred, distally rugose, brown in mass. Calyptrae cucullate, smooth, golden except for a dark apex, covering about 3/4 of the capsule.

Discussion:

(Figs. 1-8)

I have taken up Theriot's herbarium name for this species. Although Theriot (1932) enumerated the collections of M. Saint-Pierre and described many new species from them, there is no mention in his paper of this name or of the collection number. Nevado de Toluca is a large, isolated volcanic mountain, 4600 m tall.

Astomiopsis saint-pierrei is easily recognized by its leaves which are oblong- lanceolate with recurved margins and a percurrent costa. The capsules are im- mersed and have a well-developed, deciduous annulus. The calyptra is large and cucullate.

When describing A. pacifica, Buck and Landrum (1977) postulated that it might have an ephemeral life cycle. This speculation was based on the diminutive size of the plants and the fact that they were collected during the rainy season. Also, no growth from previous seasons was apparent as is also true for A. sinensis. Astomiopsis saint-pierrei, however, is definitely perennial. Still attached to the new growth, but buried in the soil, are remains of two to three previous season's growth. On the female branches the old vaginulae are always persistent and frequently old, deoperculate capsules remain. As antheridia are fragile structures, only the distinctive, differentiated perigonial bracts are present. On both types of branches the new growth arises from subfloral innovations which slightly displace the old growth to one side.

The types of the two original species of Astomiopsis, A. amblyocalyx C. Mull. and A. subulata C. Mull., are probably lost; they are not in Fleischer's herbarium at the Farlow Herbarium. Brotherus (1924) did not illustrate the genus, which probably means that he had not seen any material. However, Muller (1882) gave full descriptions. Material of A. sinensis Broth., although not illustrated, is readily available, as it was distributed as number 2973 of Zahlbruckner's Kryptogamae exsiccatae. Although described by Brotherus (1929) as having an immersed capsule, the type material in the exsiccati at the New York Botanical Garden has plainly exserted ones.