Campanella aequatorialis Singer

Honan, Amy H., Desjardin, Dennis E., Perry, Brian A., Horak, Egon & Baroni, Timothy J., 2015, Towards a better understanding of Tetrapyrgos (Basidiomycota, Agaricales): new species, type studies, and phylogenetic inferences, Phytotaxa 231 (2), pp. 101-132 : 121-122

Campanella aequatorialis Singer , Nova Hedwigia 26: 869. 1976 [1975]. Fig. 8a–c

Synonyms: Pterospora aequatorialis (Singer) E. Horak, Sydowia 36: 129. 1983.

Tetrapyrgos aequatorialis (Singer) E. Horak, Sydowia 39: 101. 1987 [1986].

Holotype:— ECUADOR. Tungurahua, Rio Verde, elev. about 1600 m, on decaying stems of Pennisetum sp. ( Poaceae ), 26 April 1973, R Singer B 7128 ( F!).

The holotype specimen consists of 2 intact, spathuloid basidiomes with laterally attached pileus. Description of dried holotype: Pileus 2–3 mm diam., cream-colored. Hymenophore nearly poroid with a few major lamellae and numerous, slightly lower cross-lamellae, edges crystalline. Stipe absent. Basidiospores only one seen, 9 × 6 μm, subangular, smooth, hyaline, inamyloid, thin-walled. Basidia not observed. Pleurocystidia absent. Cheilocystidia of two types: 1) irregularly cylindrical or lobed cells 24–30 × 4–8 μm, covered overall with coarse to fine diverticula; 2) irregularly cylindrical or lobed cells 36–60 × 5.5–9.5 μm, with a smooth bulbous apex 8–9.5 μm diam., and coarsely diverticulate central axis, some with the capitulum thick-walled; all cystidia hyaline, inamyloid. Pileipellis a well-developed Rameales -structure of densely diverticulate hyphae 2.5–5 μm diam.; diverticula crowded, 0.5–1 × 0.5 μm, knob-like to wart-like or short-cylindrical; cells hyaline, inamyloid, thin-walled, non-gelatinous; terminal cells like the cheilocystidia but all thin-walled. Pileus trama of subparallel to interwoven, strongly gelatinized hyphae 2.5–5 μm diam, cylindrical, hyaline, inamyloid, clamped.

Habitat and known distribution: On grass stems. Ecuador.

Status: This is one species that spans the morphological boundaries between Tetrapyrgos and Campanella . The pileipellis and cheilocystidium morphologies suggest Tetrapyrgos (with smooth bulbous apex and central diverticula), whereas the lack of a distinct stipe and the subangular (not tetrahedral) basidiospores in combination with strongly gelatinized tramal tissues suggest Campanella . The entirely smooth, metuloid hymenial cystidia illustrated by Singer (1975b: Fig. 1 ) were not observed. Until further material of this morphologically intermediate taxon is collected and sequenced, we accept the species in Campanella as placed originally.

Figures

FIGURE 1. Maximum likelihood (-lnL = 3590.75887) topology of Tetrapyrgos specimens sampled as part of this investigation based on ITS sequence data. Numbers separated by “/” represent non-parametric maximum likelihood bootstrap (BS) proportions and Bayesian posterior probablilites (PP), respectively. Branches highlighted in bold received combined support values of ≥70%/0.95.

FIGURE 8. Anatomical features for: Campanella aequatorialis (Singer B7128—Holotype a–c). a. Basidiospore. b. Two types of cheilocystidia. c. Pileipellis terminal cells. Singer (B1546) material of Campanella alba (d–e). d. Basidiospore. e. Cheilocystidia. Lagerheim (31 January 1892) material of Campanella alba (f–g). f. Basidiospores. g. Cheilocystidia. Campanella candida var. stipitata (Singer T1760—Holotype h–j). h. Basidiospores. i. Basidioles. j. Two types of hymenial cystidia. Scale bar = 10 μm. Illustrated by D.E. Desjardin.