Asterella abyssinica (Gottsche) Grolle
  • Explor. Hydrobiol. Bassin Lac Bangweolo Luapula Résultats Sci.


Cite taxon page as 'WFO (2020): Asterella abyssinica (Gottsche) Grolle. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-0001212978. Accessed on: 06 Jul 2020'

Diagnostic Description

It is easily recognized by the rather flattened round discs of the carpocephala, by horizontally protruding pseudoperianths, their rather short segments becoming free at the tips before the capsules dehisce.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 2
    • ]. 

    Morphology

    Thalli smallish to medium-sized, in crowded mats; green to light olive-green, hardly areolate, air pores not visible, margins hyaline or tinged with mauve to deep purple, weakly scalloped, slightly undulate; when dry, thallus margins flat or raised to partly inflexed. Branches simple or once pseudodichotomously furcate, with apical or ventrolateral innovations, widening gradually from a stipitate base, 15-18 mm long, 2.3-5.0 mm wide, 400-450 (-630) µm thick medianly, in section 6-11 times wider than thick, apex slightly notched, tips of few ventral scales recurved over edge; groove absent, thallus dorsally flat, margins acute, thin; flanks sloping obliquely, entirely or only distally purple; ventral face medianly keeled, green. Scales in 2 ventral rows, obliquely triangular, in different shades of mauve to purple, body up to 800 µm long, margins ± entire, base occasionally crescentic, 650-750 µm wide, narrowed above and sometimes constricted where joined to single oblong or elliptical appendage, 420-430 µm long, ± 200 µm wide basally, tapering above to conical apical cell, up to 12 small, colourless oil cells scattered throughout scale. Dorsal epidermal cells unistratose, containing chloroplasts, thin-walled, 5- or 6-sided, (40.0-)45.0-65.0(-72.5) x 22.5-37.5 µm; air pores hardly raised, simple, ± 12.5 x 10.0 µm, surrounded by innermost ring of small collapsed cells, then by 2 concentric rings of 6 or 7 larger cells in each, radial walls not thickened. Assimilation tissue 215-260 µm thick, air chambers small, empty, in 2 or 3 storeys, bounding walls chlorophyllose; storage tissue confined to keel, cells closely packed together; oil cells scattered throughout tissues. Autoicous. Androecia in sessile, thickened cushions, elongated or oval, occasionally furcate, near apex of branch or more proximally at constriction, opening above into conical papillae. Gynoecial receptacles proximal to apical notch of main branch or just proximal to stipitate innovation of apical branch, single, occasionally paired at apices of 2 furcate branches, ± sessile when young, later raised on stalk; carpocephalum rather flat to weakly convex, sub-orbicular, 3.5-4.0 mm across, above almost smooth. Stalk arising ± 1.7 mm proximal to apex of branch in apical notch, 4-5 mm long, whitish green or streaked with purple, widening slightly toward base, at midlength ± 520 µm wide, with rhizoid furrow, at summit of stalk and scattered along its length, colourless or purple paleae, up to 820 µm long, 2 or 3 cells wide basally, above 3-5 cells wide, tapering to apical cell. Involucre membranous, partly covering capsules below. Pseudoperianths extending up to 1250 µm beyond involucre, generally with 8-10 white segments, tapering to narrow tips that become free before capsule dehiscence. Sporophyte with obovoid capsule, thin-walled and lacking thickening bands. Spores 62.5-72.5 µm diam., triangular-globular, pale yellow to yellow, translucent; wing undulate, up to 10 µm wide, margin crenulate; distal face convex, reticulate, with network of ± 6 larger, primary alveoli across, ± 10-15 µm wide and extending over wing, their delimiting ridges only slightly raised and not clearly defined among the numerous walls of small, subsidiary alveoli, alveolar floor highly porate; proximal face with prominent triradiate ridge, its arms continuous from pole to wing, but not clearly extending across, each of 3 facets with numerous alveoli, larger at pole and smaller toward wing, but not clearly arranged in primary and subsidiary alveoli, floor also highly porate. Elaters 135-150 µm long, 10 µm wide in centre, slightly tapering toward rounded ends, bispiral.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 2
    • ]. 

    Habitat

    High altitudes on streambanks or on damp rocks.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 2
    • ]. 

      Bibliography

    • 1 Explor. Hydrobiol. Bassin Lac Bangweolo Luapula Résultats Sci.
    • 2 Perold, SM. 1999. Hepatophyta. Fl. S. Africa (1,1): 1 - 252.

     Information From

    Aytoniaceae
    World Flora Online Data. 2017.
    • A CC0 1.0 Universal (CC0 1.0).
    e-Flora of South Africa
    e-Flora of South Africa. v1.21. 2018. South African National Biodiversity Institute. http://ipt.sanbi.org.za/iptsanbi/resource?r=flora_descriptions&v=1.21
    • B All Rights Reserved
    World Flora Online consortium
    http://www.worldfloraonline.org/organisation/WFO
    World Flora Online Data. 2018.
    • C CC0 1.0 Universal (CC0 1.0).