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

Quail grass (Celosia argentea)

Boroco or quail grass ( Celosia argentea ) is a species of plant in the Amaranthaceae, a shrub with erect stems, maroon or green in color, requiring full sun, widely used as ornamental plants and flowers by the distinctive form of erect spikes. C. argentea has a strong stem with many branches from the lowest base to the apex to form a dense plant, but it opens and tapers upwards to a height of up to 1.5 meters, is maroon or green in color and the surface has vertical grooves. Single leaf 5-15 cm long, base and tip pointed, oval or lance-shaped and strongly veined, a main vein linear and straight with several minor veins towards the sides and curved, slightly wavy margins, upper surface maroon or green. Abundant flowers growing at the tips of branches above the leaves, sturdy, erect cylindrical, 2-15 cm long and depending on the cultivar, pointed tip, white on the underside and maroon on the top or one of these and often develop a silver sheen. Flowers are visited by bees, wasps, but...
Read more

Brown-woolly fig (Ficus drupacea)

Brown-woolly fig ( Ficus drupacea ) is a species of plant in the Moraceae, a tropical tree, cylindrical and 10-30 meters tall. The leaves are oval, up to 16 cm long, up to 6 cm wide, with petioles up to 2 cm long. The fruit is round-oval, up to 3 cm long, up to 2 cm wide, young yellow and old red. The fruit is eaten by pigeons, and pollinated by Eupristina belgaumensis . Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Rosales Family: Moraceae Tribe: Ficeae Genus: Ficus Species: Ficus drupacea
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