Name: Amanita augusta
Author: Bojantchev & R.M. Davis
Citation: N. Amer. Fung. 8(5): 2 (2013)
From the original description:
PILEUS 30–150 mm diam., hemispherical to convex when young, plano-convex to planoconcave with age; margin incurved to straight, occasionally ribbed striate near the margin; color dark brown to brown to yellow brown, sometimes yellow to grayish yellow at age, typically paler towards the margin; the universal veil forming rows of concentric warts (finer towards the edge), yellow, but fading to grayish-white with age,
easily removable, often partially or completely washed out or rubbed away, leaving the pileus partially or fully glabrous.
LAMELLAE crowded, 9–20 mm broad, white to yellowish near the cap margin, even, narrowly attached to free; lamellulae common.
STIPE 40–150 mm long, 10–30 mm wide, context stuffed, cylindrical to tapering towards the apex, often with a distinct bulb; color yellow when young, often fading to whitish at age, typically yellowish above the annulus; surface above the bulb forming scaly girdles (finer towards the annulus) with yellow apices, often fading to glabrous at age; surface above the annulus distinctly longitudinally striate.
ANNULUS superior, membranous, pendant, upper surface distinctly striate, thinning, but rarely collapsing with age, typically fimbriate, pale yellow to yellow on both sides, developing darker yellow brown zones at age.
STIPE BASE prominent bulb in most basidiomata,girdled with veil remnants, distinctly rufescent in age.
UNIVERSAL VEIL yellow.
CONTEXT white to pale yellow.
SPORE DEPOSIT white
BASIDIOSPORES (7.8–)8.5–9.3(–11.2) × (5.2–) 6.0–6.8 (–7.8) µm (mean 8.9 × 6.4 µm), Q = 1.27–1.57, Qav = 1.41 (N = 201, 6 basidiomata, 3 collections), broadly ellipsoid to ellipsoid, slightly to distinctly inequilateral in 30–40% of the cases, with a prominent lateral apiculus, hyaline, amyloid.
BASIDIA 35–62 × 8–12 µm, 4-spored, clavate; sterigmata 4–6 µm long; no clamps observed.
SUBHYMENIAL LAYER composed ofseveral layers of irregular to pyriform cells 9–31 × 7–21 µm, not clamped.
LAMELLAR TRAMA divergent, composed of filamentous to swollen hyphae 6–22 µm wide, no clamps observed.
LAMELLAR MARGINAL CELLS subglobose to sphaeropedunculate 10–33 × 7–21 µm.
PILEIPELLIS an ixocutis of densely interwoven hyphae 2–7 µm wide with the upper layer slightly gelatinized.
ANNULUS composed of filamentous cells, 2–6 µm wide, on the lower surface with clusters of inflated subglobose to pyriform cells, 10–30 × 8–24 µm, with a few inflated cells on the upper surface; clamp-connections not observed.
UNIVERSAL VEIL formed of dense filamentous hyphae 2–8 µm wide, interspersed with broadly ellipsoid to subglobose vesiculose cells, 30–80 × 14–60 µm; no clamps observed.
STIPE TRAMA acrophysalidic, composed of filamentous hyphae 2–6 µm wide and inflated hyphae 62–176 × 16–44 µm; no clamps observed.
OLEIFEROUS HYPHAE abundant, 7–20 µm wide with refractive content.