Morphologically, the taxon is characterized by the presence of a medium to considerably larger pileus with glutinous to viscid surface colored gray-orange to orange white or with paler to white margin;
adnate to shallowly adnexed, white, distant lamellae with 2-3 series of lamellulae; globose to subglobose basidiospores measuring 19-25x18-23 [micro]m in diameter; an ixotrichoderm type of pileipellis; well-developed, stalked, pleuro- and cheilocystidia; presence of one- to few-celled caulocystidia with heterogeneous contents; and lignicolous habit.
In a few genera in the Calamoideae (Korthalsia, Calamus, Myrialepis, Plectocomia and Plectocomiopsis) the bud is displaced longitudinally and is
adnate to the internode and leaf sheath above the node of origin (Fisher & Dransfield, 1977; Fisher & Mogea, 1980).
J: Tapirira guianensis--lanceolate axillary bud
adnate to the twigs.
Lamellae
adnate to decurrent, close to subdistant, with up to three sizes of lamellulae, margin slightly wavy, concolor with the sides, membranous, orange grey (6B3), greyish orange (6B4).
Pore surface yellow when young, becomes slightly brown upon bruising; tubes 3-9 mm deep, decurrent to
adnate and horizontal, frequent pores, pores angular, large, about 2-3 per mm; Basidiospores 7.5-11.3 x 4-5 um, ellipsoid or oblong, thin walled, guttulate, smooth, hyaline or pale brown in Potassium hydroxide (KOH), inamyloid.
The leaves are sessile, alternate, with a stipule
adnate to the leaf base, which wraps the stem (Fig.
Lamellae broad,
adnate to adnexed, white, margin entire, crowded in younger specimens, at maturity two zones, outer crowded with several tiers of lamellulae while inner has distant to sub-distant arrangement without lamellulae.
Basidiocarp resupinate,
adnate, effused, up to 250 [micro]m thick in section; hymenial surface smooth, yellowish white to pale yellow when fresh, pale orange to orange white on drying, margins thinning, paler concolorous, to indeterminate.
Corolla gamopetalous, tubular-campanulate, infundibuliform, campanulate or hypocrateriform, sometimes with bilabiate apex, aestivation imbricate, zygomorphic; stamens included or exserted, 4, rarely reduced to 2, didynamous, staminode reduced, glabro, rarely elongate and pilose; filaments
adnate to the corolla at the base; anthers commonly divergent, generally glabrous, rarely pilose; pollen grains many, in monads, rarely in tetrads or polyads; nectariferous disk generally present; gynoecium bicarpellate, bilocular; ovary superior, multiovulate, placentation axial, stigma bilamelate, lobes sensitive (closing after contact with pollinator).