Boletellus

According to Murrill's definition of the genus, species of Boletellus have an annual fruit body that grows on wood and a stem that is centrally placed. The cap surface is floccose-verrucose (covered with tufts of hairs or warts) and yellowish. The fruit body flesh is light colored and fleshy. The tubes on the underside of the cap are angular, depressed, yellowish, and covered with a partial veil. The spores of Boletellus are oblong to ellipsoid, smooth, and rust-colored. The stem is solid (i.e., not hollow), white, and not reticulate.[3] Additional characteristics of the genus have been delineated or amended since its original description over 100 years ago: spores have longitudinal ridges or "wings", are inamyloid, and rarely dextrinoid (staining deep reddish to reddish brown in Melzer's reagent). Species usually have hymenial cystidia present, and clamp connections are typically absent (with the exception of B. fibuliger).[5]

Murrill placed Boletellus ananas (formerly Boletus ananas) as the sole and type species.[3] Singer's fourth edition (1986) of his Agaricales in Modern Taxonomy included 33 species, which were classified into sections depending on moisture content, scaliness of the cap or amount of ornamentation on the stem.[6] Although some species of Boletellus are rated as edible, none are considered choice.[4]

In general, Boletes usually have smooth spores, but Boletellus, Austroboletus, Strobilomyces, and Heimioporus are exceptions to this. Hemioporus species have pitted or reticulate spores, Strobilomyces species have spiny and reticulate spores, and Austroboletus species have pitted spores, in comparison to the ridged spores of Boletellus species.[7]

B. ananaeceps

B. obscurecoccineus

Here is a list of species currently accepted in the genus Boletellus:[5]

• Boletaceae at The New York Botanical Garden
• "Boletellus Murrill". Atlas of Living Australia.