Hyphoderma praetermissum (P. Karst.) J. Erikss. et Strid, The Corticiaceae of N. Europe, 3: 505. 1975.
Description：
Macroscopic characters: Basidiocarps resupinate, effused, adnate, 100–350 μm thick, 0.5–2 × 5–20 cm, ceraceous or membranaceous, even, not cracked, white, marguerite yellow to cream color, turning cream buff in 5% KOH; margins thining out, pruinose or tomentose, white.
Microscopic characters: Basal layer with a few or much thicker parallel hyphae, up to 50 μm thick, loosely or densely parallelly arranged, with the lateral hyphae ascending in right angle; intermediate layer of context more or less distinctive, with clamp connections; leptocystidia protruding, interwoven, about 75 μm thick; hyphae 2.5–3 μm thick, thin-walled, smooth, 12.5–30 μm high, 6.3 μm wide, cylindrical, thin-walled, smooth, rounded or capitate at apex, slightly attenuate, arising from subhymenium, with wall thicker than gloeocystidia, and wider than gloeocystidia in protruding portions; gloeocystidia long obclavate or cylindrical and attenuate toward apex, more or less flexuous, gradually broader downwards and swollen at base, 6–12.5 × 75–137 μm, not protruding or slightly protruding, with the protruding portions in 2.5–5 μm width, thin-walled, deeply stained by phloxine, smooth, arising from short lateral and vertical hyphae; stephanocysts (caliciform bodies) unequally two-globose-celled, in pyriform, 10 × 14 μm, with a girdle of 10 digitate processes around the septa between two cells, and with the processes in 1–2 μm length, arising from lateral branches of basal paraphyses, gloeocystidia and leptocystidia in palisade; basidia 7.5–8.5 × 25–40 μm, subclavate, bearing 2–4 basidiospores; sterigmata curved, 5 μm long; paraphyses subclavate to cylindrical, 7.5 × 25 μm; basidiospores suballantoid to narrowly oblong, 4–4.5 × 8–10 μm, smooth, thin-walled, non-amyloid.
Specimens：
Taipei Hsien, Pinlin Hsiang, from Orchid Valley to Mt. Suchuanglo, on the road slide, under the hardwood forests, associated with Poria sp., alt. 400–500 m, Dec. 7, 1975, S.-H. Lin (NTU-3156), on the wooden bridge, under the hardwood forests, alt. 400–500 m, Dec. 7, 1975, S.-H. Lin (NTU-3158); Taipei Hsien, Mt. Seven-star, on the road side, under the hardwood forests, alt. 700 m, Dec. 6, 1975, S.-H. Lin (NTU-3856).
Habitat：
On the dead branches of broad-leaved tree and wooden bridge, associate with white rot.
Distribution：
Europe, North America, Australia, New Zealand and Taiwan.
References：
Lin, SH. and Chen, ZC. 1990.
Provided：
S. H. Lin
Note：
The species has three kinds of cystidia; leptocystidia, gloeocystidia and stephanocystidia. The leptocystidia are arising from subhymenium, frequently protruding, in cylindrical shape, rounded or capitate at apex, thin-walled but thicker when compared with gloeocystidia, and often empty without contents, thus easily confused with protruding gloeocystidia. The gloeocystidia are densely immersed in context, elongated, cylindrical and swollen at the base, arise from lateral branches of the basal hyphae, and have contents easily stained by phloxine. According to Price's observation, the gloeocystidia did not darken in sulfoaldehyde solution. The stephanocysts are only found in the thin fructification of one specimen (NTU-3856) of the collections. It may be reasonable to say that the occurrence of the stephanocysts in thin fructification may relate with the loose structure of the context of the thin and young fructification. In the specimen studied stephanocysts were found at the basal layer of context, although Price (1973) described that they were distributed throughout the fructification, i.e., in the context and hymenium. However, we agree with his opinion that the stephanocysts is probably a peculiear form of gloeocystidium. Rogers and Jackson (1943) also found that there were numerous intergrading structures connecting caliciform bodies (stephanocysts) with simple globoid gloeocystidia.
Between Hyphoderma praetermissum and Corticium torquatum, we find no critical difference. Therefore, we reduce C. torquatum as a synonym of H. praetermissum. Stephanocysts and leptocystidia are diagnostic features for distinguishing this species from others. But when the stephanocysts have not yet formed in the fructifications, it is easy to misidentify.
Phylum：Basidiomycota >> Class： Basidiomycetes >> Order： Polyporales 
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