Home

Macrospermum

Generic name: MACROSPERMUM Komárek, 2008. Fottea 8(1): 81
Synonyms:
Diagnosis:
Komárek(2008): Genus cyanobacteriis heterocytosis. Filamenta solitaria, libere natantia vel in strata irregularia, macroscopica aggregata, sine vaginis, vel cum muco incolore, tenue, amorpho circumdatae. Trichomata uniseriata, plus minusve recta vel irregulariter flexuosa, not ramosa, symmetrica vel subsymmetrica, ad dissepimenta constricta, ad apices paucim attenuata vel cylindrica, cum heterocytis duobus subapicalis, raro cum heterocyta tertia centrali. Cellulae cylindricae vel paucim barriliformes, plus minusve isodiametricae vel longior quam latae, contentu aerugineo, homogeneo, cum granulis sparsis et aerotopis solitariis facultativis; cellula terminalis cylindrica vel conica, apice rotundata. Heterocytae intercalares, solitariae, cylindricae, plerumque latior quam cellulae vegetativae, in trichomatibus subapicaliter dispositae, rare plus una heterocyta centralis. Akinetes late ovales, intercalares, cum heterocytis conjunctae, valde ad eos partes externis dispositae, solitariae, rarissime binae, cum episporio laevi vel ornati, praecipue duas in una trichoma. Reproductio trichomatibus fragmentatione et akinetis germinatione.

Etymology:
Type species: Macrospermum volzii (Lemmermann) Komárek 2008. Fottea 8(1): 82
Descriptions:
Komárek(2008): Cyanobacterial, heterocytous, filamentous genus. Filaments are free-living, solitary, in small irregular clusters or in fine macroscopic mats. Trichomes have symmetric to subsymmetric structure with two subapical heterocytes and sometimes with one ± central heterocyte; they are nearly straight or irregularly coiled with fine, colourless, diffluent and indistinct slime, uniserial, unbranched, ± cylindrical, constricted at crosswalls, sometimes narrowed to the ends and in distinct central parts. Cells cylindrical or slightly barrel-shaped, ± isodiametric or rather longer than wide, with blue-green, homogeneous content with scarce granules and facultatively with solitary aerotopes; terminal cells are rounded, conical or narrowed and bluntly pointed. Heterocytes always solitary, intercalar, cylindrical, usually wider than vegetative cells, usually two in subapical position in a trichome, or with the third heterocyte ± in the middle of a trichome. Akinetes widely oval, developing from several neighbouring cells, large, solitary, rarely in pairs, always attached to outer heterocytes; in one trichome develop usually only two akinetes, outside from heterocytes, rarely also at the “inner” side of a heteocyte.
Genotype differences, molecular
data:
Reproduction strategies, life
cycles, cell division:
Komárek (2008): Reproduction by fragmentation of trichomes and by akinetes.
Ultrastructure:
Taxonomic position, higher hierarchy:
Ecology, ecophysiology, ecological
significance:
Physiology and biochemistry:
Distribution, endemism, problematic
citations:
Reference strain:
Infrageneric scheme, species concept:

List of species:

Macrospermum fuellebornii (Schmidle) Komárek 2008. Fottea 8(1): 82
Macrospermum mysorense (Gonzalves et Kamat) Komárek 2008. Fottea 8(1): 82
Macrospermum unisporum (Gardner) Komárek 2008. Fottea 8(1): 82
Macrospermum volzii (Lemmermann) Komárek 2008. Fottea 8(1): 82

Unclear taxa: 

Keys:
List of stains:
Drawings:
Komárek 2008
Application technology:
Literature:
  2.1 taxonomy: Komárek 2008
  2.2 cytomorphology:
  2.3 16S rRNA sequencing:
  2.4 biology and life cycles:
  2.5 ecology: