Skip to main content

Lilliput brittlegill (Russula lilliputia) and Pakaraimaea brittlegill (Russula pakaraimaeae)

Lilliput brittlegill (Russula lilliputia) and Pakaraimaea brittlegill (Russula pakaraimaeae)

NEWS - Two new species of Russula from Guyana with small basidiomata: lilliput brittlegill (Russula lilliputia) and Pakaraimaea brittlegill (Russula pakaraimaeae) found in association with the hosts Dicymbe altsonii and Pakaraimaea dipterocarpacea were identified as new species based on a combined approach of morphological characterization and molecular analysis.

Ectomycorrhizal fungi (ECM) have historically been considered underrepresented in Neotropical forests, however, pockets of forest occupying the white sands region of the central Guiana Shield of Guyana are dominated by leguminous ECM trees that support an extraordinary diversity of fungi.

Russulaceae comprise the largest number of species in this region. The discovery of two new species of Russula expands our understanding of fungal diversity and the genus Russula in particular, along with the biogeography and ecosystem dynamics of often undercollected tropical forests.

R. lilliputia has small basidiomata and a fruiting habit that reaches 1.5 meters high on tree trunks, making it an exceptional fungus. The species complex of R. annulata and R. radicans in Africa is known as "lilliputiennes" because of its small size, but the basidiome of R. lilliputia is much smaller, possibly the smallest Russula ever described.

This species is characterized by a very small red pileus, not exceeding 5 mm, a solid stipe with pruinose and pileus when dry, production of basidiomes on the stem surface of D. altsonii, spores with indistinct suprahilar plage, sparse and low interconnections between verrucae, long hair-like pileocystidia arising from the epithelioid layer of swollen cells and a white spore cast.

R. lilliputia is known from only one large collection, the Upper Potaro Basin of Guyana. The type collection consists of all stages of basidiome development including about 30 individual basidiomata and primordia spread over an area of 0.5 m2 of stem surface.

R. pakaraimaeae is characterized by a 5-17 (25) mm pileus, occurring in the Upper Mazaruni Basin of Guyana in marginal forests around the Pegaima savanna in association with P. dipterocarpaceae and possibly D. jenmanii, fruiting habit with a single branching or rhizoidal base attached to large fallen leaves and organic debris. The species is solitary or in small groups in December.

Pileus dark red to purple-brown with pruinose white margins when young, stipe thick when wet then with prominent fibrillar squamules often pink when dry, spores isolated verrucous without interconnection and distinct suprahilar plage sometimes forming a partial collar on the apicululus, long hair-like pileocystidia arising from scattered swollen cells.

Original research

Steven L. Miller, M. Catherine Aime & Terry W. Henkel (2024). Russulaceae of the Pakaraima Mountains of Guyana 5. Two newly described diminutive species in a novel lineage of the crown clade of Russula (Russulaceae), Phytotaxa 668 (2): 117–129, DOI:10.11646/phytotaxa.668.2.1

Dlium theDlium
Labels:

Popular Posts

Giant golden spider (Nephila pilipes)

Kemlanding or giant golden orbweaver ( Nephila pilipes ) is an animal species in the Araneidae, a web spider with a vertical and asymmetrical mesh, sexually dimorphic with elongated females up to 20 cm in size and has a large investment in egg production and web construction, whereas males only a few millimeters. N. pilipes displays female gigantism and male dwarfism. Females usually have a body size of 30-50 mm, the cephalothorax is 15 mm long and 10 mm wide. The stomach is 30 mm long, 15 mm wide and is mostly tawny with yellow stripes. The female has black or brown, covered in thick hairs. The two rows of eyes stick out towards the back. Plastron is mostly black and brown. The legs are very long, stick-shaped with several joints, black and yellow, lacking of hairs. Males are 5-6.5 mm in size, cephalothorax is 2.5 mm long and 2 mm wide. The stomach is 4 mm long and 1.5 mm wide. The front eye is bigger than the back eye. The legs are light brown with some hair. Yellow carapace with ...
Read more

Wild durian (Cullenia exarillata)

Wild durian ( Cullenia exarillata ) is a species of plant in the Malvaceae, a tall tree with smooth, greyish-white bark, peeling on older trees, a straight trunk, horizontal branches and often with a series of knob-like tubercles for flower and fruit attachment. C. exarillata has young branches and the underside of the leaves is covered with golden brown peltate or shield-like scales. The leaves are single, alternate, glabrous, glossy green on the upper side and covered with silvery or orange peltate scales on the underside. Hermaphroditic flowers are tubular and also covered with golden brown scales, 4-5 cm long and cream or reddish brown in color. Flowers have no petals, formed of tubular bracteoles and tubular calyxes, 5-lobed. Fruit is round, 10-13 cm in diameter, covered with thorns and clustered along the branches. Many seeds, reddish brown, 4-5 cm long and 2-3 cm wide. The seeds are enclosed by a fleshy, whitish aril. The fruit splits open when ripe and dries to release the s...
Read more

Khayu shield bug (Pycanum oculatum)

Khayu shield bug ( Pycanum oculatum ) is an animal species in Tessaratomidae, arboreal insect, has wings, wide elliptical body, dark brown, black and ivory, spends time perched on leaves in bushes and low trees in forests and land agriculture. P. oculatum has an egg-shaped body, wide, flat upper surface, circular shoulders that form a semicircle, the rear end ends at the wing. The front has a thin black margin. The upper surface is covered by the folds of the wings leaving a visible edge, has a dark brown color and has a vein stripe. Along the margins on the sides have black and ivory stripes. The lower surface is the belly, is convex elongated, the front has folds, the back has straight transverse folds, is dark brown with light brown parts and the margins have black dots. The head on the front end, small size, triangular shape with a pair of black and light brown eyes on each side. A pair of antennae appears on the side of the head, in the shape of a cylindrical stick, has four se...
Read more