Asterella

  • Authority

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

  • Family

    Melanommataceae

  • Scientific Name

    Asterella

  • Type

    Lectotype (Zijlstra, 1993). Marchantia tenella L. [= A. tenella (L.) P.Beauv.] (typ. cons.). From Aster = star, -ella = little, referring to the starlike carpocephala with radiating pseudoperianths.

  • Synonyms

    Fimbraria Nees, Fimbriaria Steud., Hypenantron, Marchantia tenella L., Asterella tenella (L.) P.Beauv.

  • Description

    Genus Description - Thallus prostrate, sometimes with pungent "fishy" smell, green, often purplish pigmented especially beneath, thin and delicate or thick and leathery. Branching of terminal apical adventitious branches, terminal branches or stipitate-based ventral branches. Epidermal pores slightly elevated, simple, with 4-8 radial rows of cells in concentric rings, radial walls of cells sometimes somewhat thickened but not stellate. Assimilatory tissue of 1 to several layers of overlapping air chambers that are empty or subdivided by secondary walls. Ventral tissue often mycorrhizal; oil cells scattered. Rhizoids smooth and pegged. Ventral scales in 2 rows on midrib, colorless or violet to purplish pigmented, asymmetrical, with 1 or 2 lanceolate to ovate appendages often somewhat constricted at base, with scattered oil cells in body and sometimes in appendage, margin with few to many slime-papillae. Asexual reproduction by specialized propagules lacking, but sometimes with tuberous persistent branch tips. Monoecious or dioecious. Antheridia scattered or in cushions on main thallus or main or reduced branches. Archegonia in cushions bounded by scales, 2-4 per archegonial cavity, terminal on main thallus or on large or reduced ventral branches. Archegoniophore stalk elongating after fertilization, with or without air chambers, with a single rhizoid furrow, with or without scales at top and bottom. Receptacle of mature archegoniophore subglobose when young, becoming conical, ovoid or inversely saucer-shaped when mature, 2- to 6-lobed, with compound pores. Involucres flaplike, usually hidden beneath lobes; involucres opening obliquely downwards. Calyptrae 3-to 4-layered. Sporophytes 1 per involucre, with bulbous foot and scarcely elongating seta, enclosed by a colorless or pigmented pseudoperianth consisting of a unistratose basal cup and 5-18 lanceolate lobes attached at apex when young, remaining attached or becoming free at maturity. Capsules globose, dehiscing when ripe in upper 1/3-1/4 as an irregular or regular, discoid cap, wall without thickenings. Spore/elater ratio 4:1. Elaters with 1-3 helical bands. Spores 2000-4000 per capsule, 55-150 µm diam., yellow, orange, brown, or black, proximal and distal surfaces with similar or dissimilar sculpturing, areolate, alveolate, or ridged, sometimes with equatorial pores, trilete mark distinct. Gametophytic chromosome number mostly n = 9.