Monographs Details: Syrrhopodon xanthophyllus Mitt.
Authority: Reese, William D. 1993. Calymperaceae. Fl. Neotrop. Monogr. 58: 1-102. (Published by NYBG Press)
Synonyms:Heliconema xanthophyllum (Mitt.) L.T.Ellis & Eddy
Description:Species Description - Plants small, slender, glossy; rhizoids dark-purple; stems to 2 cm tall. Leaves ligulate to acuminate with mostly broadly mucronate apices, 2.7-3.5 mm long from reddish-brown, glossy, scarcely broader bases, involute and curved when dry, ascending and more or less tubulose when moist, lying straight on slide but with base usually folded; margins of upper lamina thickened, irregularly serrate to serrulate, often with low, obscure, paired teeth, lacking stereids in section, margins of lower lamina nearly entire to regularly serrate with sharp teeth, often bordered with several to many rows of elongate cells; cancellinae fragile, quickly eroded and ephemeral, small and not clearly demarcated, obliquely truncate distally and longer at leaf margins than at costa; median leaf cells thick-walled, rounded-square or elongate, mostly ca. 8 µm, nearly smooth or with low papillae dorsally, strongly bulging ventrally; gemmae scarce, borne ventrally along costa and leaf margins between shoulders and leaf tip, mostly 100200 µm long, clavate, fusiform, or filamentous with thick, dark-brown cell walls. Sporophytes completely immersed; seta very short; capsule 1 mm long; peristome lacking; operculum 0.7 mm long. Spores 17-21 µm, finely granular. Calyptra minute, ca. 0.5 mm long, conical, extending down only to base of rostrum, papillose above.

Discussion:Among other features, the colored leaf bases, lack of peristome, and ephemeral cancellinae distinguish this little moss from 5. cryptocarpos; its cancellinar cells also lack the distinctive thickenings of those of S. cryptocarpos. It seems to be most closely related to S. rigidus, of which it is a miniature version except for its sporophyte. Although Ellis (1989) assigned S. xanthophyllus to Heliconema Ellis & Eddy, its relationships lie not with S. cryptocarpos but with S. rigidus and its allies (Reese 1977). See discussion under S. cryptocarpos for further comments on S. xanthophyllus.
Distribution:Venezuela South America| Amazonas Venezuela South America| Brazil South America| Amazonas Brazil South America| Pará Brazil South America| Rondônia Brazil South America| Bolivia South America| Beni Bolivia South America|