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 Helicogermslita mackenziei
BiostatusPresent in region - Indigenous. Endemic
Images (click to enlarge)
Caption: Fig. 2 A-C, Astrocystis cyatheae, PDD 49673: A, Ascospores, the lowest immature (1st, 2nd
from type, PDD 49672); B, Ascus apical ring; C, Conidiophores and conidia on the stroma
(PDD 42074); D, H. aucklandi | 
Caption: Fig. 6 Helicogermslita mackenziei. A-D, F, G, I, Stromata, A, B, F, young stromata emerging
from wood; E, H, Vertical sections |
Article: Petrini, L.E. (2003). Rosellinia and related genera in New Zealand. New Zealand Journal of Botany 41(1): 71-138 (http://www.rsnz.org/publish/abstracts.php).
Description: Stromata (475)530 ± 54(600) µm high, (575)620 ± 33(650) µm wide (n = 5), breaking through the wood, covered with white or brown remnants of host epidermis, conical to semiglobose, black, with surface shrivelled or finely cracked, single, forming small groups, on wood free, otherwise immersed in bark and only ostioles exposed. Ostioles finely papillate or not pronounced, seldom seated on a disk. Ectostroma 50-75 µm thick, black. Entostroma dark brown, soft, confined to base. Perithecia detached and collapsed in mature material. Ascus apical rings 4.8-5.8 µm high, upper width 5.7-6.7 µm, lower width 4.8-6.7 µm (n = 4), almost rectangular, without bulge at upper margin, upper end blurred, J+, light blue. Ascospores (20.2)23.4 ± 1.4(25.5) µm long, (9.6)11 ± 0.7(12.5) µm wide (n = 30), ellipsoidal with broadly rounded ends, dark brown, with sigmoid germ slit running almost over the whole spore length, occasionally with a basal, 0.5 x 0.5 µm large, semiglobose, cellular appendage.
Anamorph unknown.
Habitat: HOST: Undetermined.
MATRIX: On bark or wood of small heavily decomposed twigs, c. 1 cm diam.
Notes: ETYMOLOGY: In honour of one of the collectors, the New Zealand mycologist E. H. C.
McKenzie.
NOTES: Helicogermslita mackenziei has ascospores with a sigmoid germ slit. The stroma
ontogeny and morphology and the ascus apical rings, however, are similar to those of the
other two species that have coiled germ slits, thus, a placement in Helicogermslita is justified.
The specimen PDD 71919 has larger stromata than the type specimen, but they do not differ in
ascospore size and morphology. Therefore, the specimens are considered as conspecific.
Helicogermslita aucklandica, represented by a specimen from the Cooke herbarium (K), has
similar but statistically significantly smaller and more broadly rounded ascospores than H.
mackenziei.
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