Cyathodium steerei Hässel

Authority

Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)

Family

Cyathodiaceae

Scientific Name

Cyathodium steerei Hässel

Type

Type. Argentina. Tucumán: Valley of Río de las Sosas, El Nogalar, 4 Dec 1960, Hassel de Menéndez 390 (holotype, BA).

Description

Species Description - Thallus bright green, thin, with a midrib, 2.5-8.0 mm long, 1.5-3.0 mm wide, dichotomously branched, marginal cells slightly crenulate, with specialized idioblasts between 2 or each consecutive cell, decomposed in older portions of thallus. Dorsal epidermis delicate, cells lenticular, markedly bulging internally into air chambers, thin-walled, chlorophyllous, at midthallus 36-60 µm diam., oil bodies brown, in specialized cells devoid of chloroplasts, 28-30 µm diam. Epidermal pores simple, increasing in size in older portions of thallus, 120-180 |um diam., surrounded by 1-3(-4) rings of thin-walled cells, projecting slightly above surface, uppermost ring of 5-21 cells abutting like papillae into pore, second and third (-4) rings of cells incomplete, with 5-10 elongate cells. Ventral epidermal cells elongate, thin-walled, at midthallus 60-96 µm long, 24-26 µm wide, longer and wider toward base; multistratose area present in tubers and near antheridial receptacles, with few chloroplasts, without oil bodies. Rhizoids of 2 types, wide and slightly undulate, and narrow with spiral twisting and tuberculate. Ventral scales lanceolate, 5-7 cells long and 2-3 cells wide with 1-6 marginal cells with a brown oil body. Dioecious. Antheridial receptacles apical, hemispherical, without lobules, rugose, nearly sessile, 1-1.5 |im diam., surrounded at base by scales. Involucres to 2 mm long, with 5-10 archegonia, sac-like, opening by 2 lips apically, marginal cells with sinuous walls, brownish, ventral surface with scales. Sporophytes 1 per involucre, operculum of 4 thick-walled central cells and inner tier of 8-9 cells with annular thickenings (Srivastava & Dixit, 1996). Spores brown, 33-40(-44) µm diam., with irregular lamellae, 7-19 µm long, 2-6 µm high, upper border sinuous. Elaters reddish brown, 600-780 µm long, 16-19 µm wide, attenuate at both ends, with 3-4 spirally thickened bands, bispiral at extremes. Vegetative propagation by tubers with triangular or rounded imbricate, lunulate lobules, scales, and rhizoids.

Discussion

Cyathodium steerei is similar in spore ornamentation to C. spruceanum, but thallus size, presence of oil bodies in idioblasts, number of opercular cells, and the presence of inner and outer involucral scales readily distinguish C. steerei from its sister species.

Distribution and Ecology: The species is known only from Argentina and grows on soil and on rock covered by thin soil. It is possible that with further collecting the range of the species will extend to other neotropical countries.

Distribution

Tucuman Argentina South America|