Boletales » Boletaceae » Phylloporus

Phylloporus megacystidiatus

Phylloporus megacystidiatus L. Ye, P.E. Mortimer, J.C. Xu & K.D. Hyde

MycoBank number: MB804643


Pileus: 30-55 mm diameter, convex to applanate and depressed or infundibuliform at the centre. The surface is dry, smooth and then squamulose with age. The pileus has light yellow (2A5) and light brown (6D8) scales points. The margin is inrolled when young and becomes uplifted with age. Context: 5-6 mm thick and soft. The creamy to yellowish color does not change with injury. Lamellae: 6.5-12 mm wide, subdistant and commonly anastomosing. The lamellae are light yellow (2A5) and deeper yellow (2A8) in color, with older fruiting bodies exhibiting an orange yellow (4A8). They become greenish-blue when injured. The lamellulae are crowded, common and the same color as the lamellae. Stipe: 25-31×5-7 mm, central, subcylindric to cylindric and solid to fistulose. The surface is dry, smooth to tomentose, white (A1) and orange white (5A2). Annulus and volva: absent. Basidia: 32-42×9-12 μm, four spored, clavate, thin-walled, colorless or yellowish in KOH; sterigmata 4-5 μm in length. Basidiospores: [50/2/2] 10-12×3-5 μm. Some spores are slightly thick-walled and subfusiform to subclavate. They are yellowish and appear smooth under a light microscope. Pleurocystidia: 84-110×11-14 μm, abundant and subfusiform to fusiform. They are thick-walled and yellowish with no encrustations. Cheilocystidia: 94-181× 10-17 μm, abundant, subfusiform and thick-walled. They are colorless in KOH and have no encrustations. Pilleipellis: a trichoderm composed of compact, branched hyphae, which are smooth and yellowish or colorless in KOH. The terminal cells are 112-127×25-49 μm and narrowly clavate. Stipitipellis: a trichoderm-like structure composed of thin to slightly thick-walled hyphae. The terminal cells are 156-255 × 32- 54 μm, narrowly clavate or clavate and colorless. Taste and smell: No special odor or taste. Spore print: light yellow and yellow.


Habitat and distribution: Solitary and found in areas planted with mixed tea. Material examined: CHINA. Yunnan Province: Xishuangbanna, Mengsong Village, UTM N2379744.485281, UTM E653217. 753714, alt. 1600 m, 19 Sep. 2012, Lei Ye, (HKAS78351, holotype).

Notes: Phylogenetic analysis showed that P. megacystidiatus is closely related to P. yunnanensis, but the fruiting bodies and a number of microscopic characteristics were disparate. The pileus of P. megacystidiatus is light yellow and the cap tissues are softer than P. yunnanensis. This new species has similar basidiospores to P. yunnanensis, but the basidia are wider (width: 9-12 μm), and the pleurocystidia are narrower. The cheilocystidia of P. megacystidiatus are also longer (length: 94-181 μm) and narrower (width: 10-17 μm) than P. yunnanensis. The terminal cells of the pileipellis in P. megacystidiatus are large (length: 112-127 μm), while P. yunnanensis has smaller (length: 52-76 μm) pileipellis terminal cells. The terminal cells of the stipitipellis in P. megacystidiatus are longer (length: 156-255 μm) and larger (size: 156-255×32-54 μm) than those of P. yunnanensis, furthermore

the stipitipellis cells in these two species always have round apices.



Fig. 1 Maximum parsimony phylogram showing the phylogenetic position of Phylloporus megacystidiatus, P. rubiginosus, P. imbricatus, P. pachcystidiatus and P. yunnanensis with some selected Phylloporus species based on ITS2 rDNA sequences. Data were analysed with random addition sequence, unweighted parsimony and gaps were treated as missing data. Values above the

branches are parsimony bootstrap (≥ 50%). The tree is rooted with Xerocomus magniporus M. Zang & R.H. Petersen.