Jianshouqing Mushroom (Boletus Luridus) in Yunnan

The Jianshouqing mushroom (学名: Suillellus luridus) is a species of fungus in the Boletaceae family, classified under the Suillellus genus. Its formal Chinese name is Red-net Bolete (红网牛肝菌), with other common names including Pale Yellow Bolete (浅黄牛肝菌) and Brown-yellow Bolete (褐黄牛肝菌).

Description

The mushroom has a meaty cap that starts off hemispherical and becomes convex or flat as it matures. The cap can reach a diameter of 12-15 cm when fully grown, with some specimens growing up to 20 cm. The colors of the cap vary widely, including shades of gray-brown, light brown, olive-brown, yellow-brown, light yellow, and various tones of red.

The stem of the mushroom is cylindrical, measuring between 6-20 cm in height and 2-5 cm in diameter. The tube-like structure beneath the cap is long and thin. In its early stages, it is pale yellow, changing to yellow-green, and eventually dark olive with maturity. The flesh of the mushroom is white or light yellow, turning green and later blue when exposed to air after being cut or broken.

Habitat and Distribution

Jianshouqing mushrooms are found in a wide range of environments, from plains to mountains. It is commonly found in both deciduous and coniferous forests, and even in urban parks. This species thrives in sunny areas and calcareous soils but can also adapt to neutral and slightly acidic soils. Apart from being common in mainland Europe, it is also found in areas of China, particularly in Yunnan (云南) and Sichuan (四川).

Culinary Use and Caution

The Jianshouqing mushroom is known for its delicious taste and firm texture, making it suitable for stews, seasoning, and oil-based preservation. However, it must not be consumed raw or undercooked as it may cause poisoning. The mushroom should be boiled before consumption, and discarding the boiling water can reduce the risk of toxicity, but it does not guarantee complete safety. If unsure of the species, it is recommended not to eat it.

Scientific Classification

• Latin Name: Suillellus luridus (Schaeff.) Murrill

• Common Names: Red-net Bolete, Pale Yellow Bolete, Brown-yellow Bolete

• Kingdom: Fungi

• Phylum: Basidiomycota

• Class: Agaricomycetes

• Order: Boletales

• Family: Boletaceae

• Genus: Suillellus

• Species: Suillellus luridus

History and Naming

The Jianshouqing mushroom has a long history in Chinese botanical records. It was first documented by Lan Mao (兰茂), a scholar from Kunming (昆明), during the early Ming Dynasty in his work Dian Nan Ben Cao (滇南本草). Lan Mao noted that the mushroom’s flesh turned blue-black upon exposure to air and had a bitter taste, which could cause stomach pain if consumed improperly.

The discoloration of the mushroom’s flesh is a result of the oxidation of acidic compounds in the mushroom, which happens when it is exposed to air. The longer the exposure, the deeper the blue color becomes. This phenomenon is referred to as the “blueing reaction.”

The species was first named Boletus luridus by German botanist Jacob Christian Schaeffer in 1774. Later, in 2015, Spanish mycologist JB Blanco-Dios described other variants of the species, and in 1909, American mycologist William Alphonso Murrill reclassified it as Suillellus luridus, which is its current accepted scientific name.

Naming Etymology

The genus name Boletus is believed to either come from the Greek word “bolos”, meaning mushroom or the shape of a mushroom cap, or from the Latin “boletus”, which refers to a round object like a soil lump or something growing from the ground. The species name “luridus” comes from Latin, meaning “ugly” or “dirty,” referring to the greenish-blue discoloration of the mushroom’s flesh when exposed to air.

In Chinese biological species listings, Jianshouqing is listed under the genus Boletus, while the Global Biodiversity Information Facility (GBIF) categorizes it under the genus Suillellus, which is the classification used in this article.

Morphological Characteristics

Cap

The cap of the Jianshouqing mushroom is meaty and initially hemispherical in shape, later becoming convex or flat as it matures. It can reach a diameter of 12-15 cm when fully grown, with some mushrooms growing up to 20 cm. The cap color is diverse, ranging from gray-brown, light brown, olive-brown, yellow-brown, light yellow, to various shades of red. The surface of the cap often shows a gradual transition of colors. The texture of the skin is velvet-like, smooth, and nearly non-sticky in dry weather, but slightly sticky in humid environments. When touched, the contact area turns distinctly blue, which is its typical chemical discoloration reaction.

Stem

The stem measures between 6-20 cm in height and 2-5 cm in diameter. It is cylindrical, typically located at the center of the cap, and slightly swollen at the base. The structure is solid and compact. The stem starts off light brown and then transitions to pale yellow, with the base being darker, ranging from dark brown to almost black, and sometimes even purple. The upper part of the stem is covered with a broad, long, red mesh-like structure, while the lower part may have red spots. Similar to the cap, the stem turns blue when touched.

Pores

The pores of the Jianshouqing mushroom are small and round, with a relatively small diameter. Initially, they are pale yellow, changing quickly to orange or red-orange, and eventually turning deep red to brick red. The pores also turn blue when touched.

Tubes

The tubes are long and thin, with the portion near the stem being shorter. Initially, they are pale yellow, changing to yellow-green, and eventually dark olive as they mature. When cut or touched, the tubes turn blue. The tubes can easily separate from the cap, and when detached, the color of the cap’s underside matches the color of the pores.

Spores

The spore print is brownish-green, with spores measuring (11-14) micrometers by (5-6) micrometers. The spores are smooth and oval-shaped.

Flesh

The flesh of the mushroom is white or pale yellow. When cut or broken, it rapidly turns green and then blue. After removing the tubes, the hidden part of the cap shows a red tone.

Distribution Range

Jianshouqing mushrooms are widely distributed, commonly found across mainland Europe, and also in regions of China, including Yunnan (云南) and Sichuan (四川).

Habitat

Jianshouqing mushrooms are commonly found from plains to mountainous areas. They are typically found in broadleaf forests (such as those with species from the Fagus (山毛榉属), Quercus (栎属), and Carpinus (鹅耳枥属) genera) and coniferous forests (such as those with species from the Pinus (松属), Abies (冷杉属), and Picea (云杉属) genera). They can even be found in urban parks.

Jianshouqing mushrooms grow in clusters or scattered groups during the summer and autumn months. They prefer sunny environments and calcareous soils but can also adapt well to neutral and slightly acidic soils.

Comparison with Similar Species

Jianshouqing (Suillellus luridus) belongs to the Boletaceae family and is related to several other species, including Red-stemmed Bolete (Neoboletus luridiformis, 红柄牛肝菌), Satan’s Bolete (Rubroboletus satanas, 撒旦牛肝菌), and Red-footed Bolete (Suillellus queleti, 红脚牛肝菌). These species are similar in appearance, but they have distinct differences, as outlined in the table below:

Scientific Name	Distinct Morphological Features	Image
Jianshouqing (Suillellus luridus, 见手青)	Cap is light soil brown or light tea brown, often cracking into small patches
Red-stemmed Bolete (Neoboletus luridiformis, 红柄牛肝菌)	Cap is brown; stem is red and covered with fine red spots, lacks mesh-like decoration
Satan’s Bolete (Rubroboletus satanas, 撒旦牛肝菌)	Cap is white
Red-footed Bolete (Suillellus queleti, 红脚牛肝菌)	Cap is reddish-brown; stem lacks mesh structure and is pale yellow

The key differences between these species are found in their cap colors and stem features. The Jianshouqing mushroom (见手青) typically has a cap that is light soil brown or light tea brown, while the Red-stemmed Bolete (红柄牛肝菌) has a brown cap with a red stem covered in fine red spots. Satan’s Bolete (撒旦牛肝菌) is characterized by its white cap, and the Red-footed Bolete (红脚牛肝菌) has a reddish-brown cap and a stem that lacks the mesh-like structure.

Toxicity of the Species

Jianshouqing (见手青) is toxic, and consuming it raw or undercooked can lead to neurological symptoms. It is not recommended to consume it with alcohol, as this mushroom can slow down the metabolism of ethanol, leading to the accumulation of acetaldehyde in the blood, which causes prolonged intoxication and nausea. Given the difficulty in distinguishing various red bolete species, if the species cannot be definitively identified, it is best to avoid consuming Jianshouqing.

Before cooking, Jianshouqing must be boiled, and the boiling water should be discarded. This is because the mushroom contains heat-sensitive substances, and boiling eliminates the toxins. However, it is important to note that boiling and discarding the water reduces the risk but does not guarantee complete safety.

Main Culinary Uses

Jianshouqing (见手青) has a delicious flavor and firm texture, making it suitable for stewing, seasoning, and pickling. It is particularly popular in local Yunnan cuisine, such as Yunnan Jianshouqing Stewed Chicken (云南见手青炖鸡).