BADHAMIA GRACILIS


Espèce: Badhamia gracilis (T.Macbride)T.Macbride.

Synonymes: Badhamia macrocarpa (Ces.)Rostaf. var. gracilis T.Macbride

Noms communs: Badhamie gracile

Sporocyste: 0,5-0,8(1,2) mm, plus ou moins sphérique, ou sphérique aplati ou réniforme, généralement stipité,
rarement sessile. Souvent en groupes, parfois assez denses. Le plasmode est blanc, selon Martin et Alexopoulos.

Pied: 1,3-1,6 mm, mince, ridé, tordu sur lui même, parfois comprimé en forme de bande, parfois couché, jaune ocre à brun jaunâtre.

Spores: noires en masse, pourpre foncé par transparence, (10)12-16 µ, avec des verrues formant un réseau à large mailles.(voir fig.13 et 14)

Habitat: le plasmode se trouve le plus souvent sur des restes de succulentes, Agavacées, etc..

Observations: une étude américaine de Clark J, Haskins EF, Stephenson SL. du Department of Biology, University of Kentucky, Lexington, Kentucky 40506.(résumée ci-dessous) a montré que B.gracilis représente vraisemblablement un large complexe spécifique.
"Sixty-four isolates that conformed to the general morphological description of Badhamia gracilis were isolated from several arid regions in the southwestern USA, northern Mexico, Puerto Rico, and the Canary Islands. These isolates were then subjected to a biosystematic study in which reproductive systems, culture characteristics, and morphology were examined. Five of the isolates were heterothallic and were divided into two separate biological species with multiple allelic mating systems: A1 consisting of three isolates (Arz 4, Arz 5, Arz 6) displaying four alleles, and A2 consisting of two isolates (NM 3, NM 4) also displaying four alleles. The remaining 59 isolates were nonheterothallic and presumably apomictic. All of the isolates had similar culture characteristics in that they had white (rarely with a yellowish tinge) plasmodia that sporulated at a relatively small size. While all of the isolates generally conformed to the standard species description, there were several variations from the norm that occurred at a high frequency. The sporotheca was often laterally flattened instead of globose or ovate, the spores generally averaged 10 μm instead of 14 μm in diam, and the capillitium often appeared physaroid instead of badhamoid. This study indicates that Badhamia gracilis is probably a widespread species complex consisting of a number of local sexual populations and numerous asexual clones that are adapted to arid conditions."

Bibliographie:S.L. Stephenson et H. Stempen - 1994. Myxomycetes - A handbook of slime molds. pp 54-91,92. sub Badhamia gacilis
H.Neubert, W.Nowotny, K.Bauman, u.m. von H.Marx - Band 2. 1995. Die Myxomyceten. pp 173-330. sub Badhamia gracilis = B.macrocarpa var. gracilis.

.