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Description type:Original description 
Description:Ramaria africana Petersen, sp. nov. Text fig. 10.
Fruit bodies up to 6 cm high, individuals up to 3 cm broad, but occuring in cespitose clusters at least 10 cm long, repeatedly branched with open, ascending but lax appearance, arising from copious rhizomorphic strands. Rhizomorphic strands white, from very slender to quite thick (up to 3 mm thick), discrete, smooth copious, often attached to or forming significant resupinate patches on substrate (up to at least 5 x 3 cm in area, but probably much more extensive). Stipe up to 4 mm thick, virtually nonexistent, branching almost immediately into primary branches flattened or lobed in crosssection. Primary branches up to 3 mm thick, lax to erect, with inferior, unilateral hymenium; secondary branches open, lax to erect, slender (up to 2 mm thick), with unilateral hymenium sharply delimited; color of branch system pale brownish-grey; apices very delicate, acerose, dichotomous, white; internodes reducing gradually; axils lunate to narrowly rounded, sterile, with sterile zone clearly delimited and extending as a line below axil. Odor and taste not recorded.
Hyphae of rhizomorphic strands of two types: a) generative, 2.5-3.7 µm diam, hyaline, thin-walled, conspicuously clamped, very inconspicuous in mounts, easily fractured; inflated clamp connections not observed, and b) skeletal, 1.1-2.2 µm diam, thick-walled, aseptate, arising from clamp connections, rigid, easily fractured, refringent under phase contrast. Hyphae of fruit body base (approx. 5 mm from substrate) of two types: a) generative 2.2-5.9 µm diam, thin- to thick-walled (wall up to 1.5 µm thick), conspicuously clamped, gnarled to some extent; inflated clamp connections up to 11.8 y broad, without significantly thickened wall, unornamented, and b) rare skeletals as in rhizomorphic strands. Hyphae of upper branch trama generative, 1.8-6.7 µm diam, thin- to very slightly thick-walled (wall up to 1.0 µm thick), more or less parallel; hyphae of subhymenium up to 2.5 µm diam, thin-walled, tightly packed, strictly parallel; hymenium apparently thickening; basidia easily crushed, 4-sterigmate.
Spores (text fig. 10) 8.1-10.4 x 4.8-5.6 µm (E = 1.69-1.93; Em = 1.80; Lm = 9.14 µm), ellipsoid to ovoid, slightly flattened adaxially, roughened in profile; contents homogeneous to obscurely vacuolate or guttulate, not refringent under phase contrast; wall up to 0.4 µm thick; apiculus narrow, prominent, eccentric, occasionally with callus; ornamentation gritty, of small, ill-defined, hardly cyanophilous areas in low patches but not accurately illustratable.
Observations: The species has a number of characters in common with Lachnocladium albocinereum from South America, including unilateral hymenium, greyish coloration, and skeletal hyphae in the fruit body base. The brown pigment seems somewhat different from that in L. albocinereum, and the spores are significantly larger.
Three characters clearly separate R . africana from R. molleriana, even though the ranges of the two organisms overlap significantly. The fruit body of R . africana includes skeletal hyphae, at least toward the base (up to 5 mm in some specimens), while such hyphae are restricted to the rhizomorphic strands in R . molleriana. Possession of skeletal hyphae in the fruit body is sharedÀ²by R. africana, R . albocinerea and R. kisantuensis, but the first two differ in fruit body color and shape, and the latter two produce smaller spores.
A second character separating R. africana from R. molleriana is spore size, with R. africana producing significantly larger spores when very accurate measurements of several specimens are compared.
The third separating character is fruit body shape. The fruit bodies of R. africana are very open, somewhat lax, with the branches rarely interfering with one another, while the branches of fruit bodies of R. molleriana are slender and much more congested. Branches of R. africana appear round in crosssection, while those of R. molleriana are lobed or channeled in cross-section.
Although I have not seen enough material of either species to be sure, the superficial mycelial mat of R. africana seems very distinct from the very abruptly disappearing mycelium of R. molleriana, which appears to arise very close to, or perhaps within, the woody substrate.
The specimen from North Borneo was misidentified as R. stricta, from which it differs in having skeletal hyphae in the fruit body, and producing slightly different spores.
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