Mushroom Lamella: Nature's Intricate Design

Mushrooms are fascinating organisms, and one of their most interesting features is the lamella, or gill, found on the underside of the cap. These papery structures are used by mushrooms for spore dispersal and play a crucial role in species identification. The word lamella refers to plate-like or blade-like structures, and in mushrooms, they are the gills of the fungus. The gills are covered with microscopic, club-shaped structures called basidia, which produce spores. The presence of gills provides a significant advantage to mushrooms by greatly increasing the surface area available for spore production. This adaptation allows mushrooms to efficiently disperse their spores and ensure the survival of their species. The arrangement and morphology of gills vary among different mushroom species, and understanding these variations is essential for accurate identification and classification of mushrooms.

Lamellae are plate-like or blade-like structures under the mushroom cap

In mycology, lamellae (singular: lamella) are plate-like or blade-like structures, often referred to as gills, found under the cap of many Basidiomycete fungi, including mushrooms. These structures are used by mushrooms for spore dispersal and play a crucial role in species identification.

The attachment of lamellae to the stem, or stipe, can vary among different mushroom species. They can be classified as free, adnexed, adnate, or decurrent. In free lamellae, the stipe is structurally distinct from the cap, or pileus, and the lamellae arise from the cap's tissues without attaching to the stipe. This type is less common and characteristic of genera like Agaricus, Amanita, and Coprinus. Adnexed lamellae are those that ascend and appear to be almost free at the point where they meet the stipe. Adnate lamellae meet the stipe at a nearly right angle, neither ascending nor descending. Decurrent lamellae, on the other hand, appear to run down the stipe, as seen in genera like Clitocybe and Cantharellus.

The arrangement of lamellae, or gills, can vary significantly among mushroom-forming species. Some species have a single array of unbranched gills radiating from the central stipe, while others produce multiple files of lamellulae (partial gills) between the primary gills, or have branched gills. The spacing between the gills, or their crowding, is another distinguishing feature. Some mushrooms have crowded gills that are very close together, making it challenging to see the spaces between them. This is typical of young specimens of Agaricus bisporus and some Amanita and Coprinopsis species. Close gills are densely arranged but with visible spaces, as seen in Russula claroflava. Subclose gills, where there is some space between the gills, are the most common arrangement in mushrooms. Distant gills, on the other hand, are widely separated and found in tiny mushrooms like Marasmius rotula.

The edges or margins of lamellae can also show interesting variations. While most mushrooms have even margins, some species have edges lined with cheilocystidia, which are cells with distinctive shapes and colours. If these cells are filled with coloured pigment, the edge of the gill will have a different colour than the sides. For example, the gills of Mycena rubrimarginata are nearly white but have red margins due to the presence of pigmented cheilocystidia.

They are used for spore dispersal and increase the surface area for spore production

In mycology, a lamella (plural lamellae), or gill, is a papery hymenophore rib under the cap of some mushroom species. They are an important feature for the identification of mushrooms. The gills are used by mushrooms as a means of spore dispersal and increase the surface area for spore production.

The branching of gills produces the same increase in surface area as the formation of free-standing lamellulae (short gills). The addition of lamellulae between every second gill would offer a slightly greater increase in surface area in comparison to the addition of lamellulae between every pair of opposing gills, but this morphology does not appear in nature. Analysis of photographs of mushrooms demonstrates an excellent match between natural gill arrangements and configurations predicted by models.

The presence of gills represents a clever adaptation that allows many fungi to expand their spore-producing surfaces. The total surface area of all the gills of a mushroom (including both sides) is much greater than the surface area of a single, flat surface the size of the mushroom’s cap. This allows for a maximum 20-fold increase in surface area for spore production.

The attachment of the gills to the stem is classified based on the shape of the gills when viewed from the side. Free lamellae are less common than attached ones but are characteristic of several genera such as Agaricus, Amanita, Coprinus, Coprinopsis, Macrolepiota, and several others. Adnexed lamellae are those that are ascending at the point at which they meet the stipe.

The gills are classified based on their attachment to the stem and their shape

The gills of a mushroom, or lamellae, are plate-like or blade-like structures that are attached to the underside of the cap of many Basidiomycete fungi, including mushrooms. They are the primary site for spore production and dispersal, and they add to the aesthetic appeal of mushrooms with their intricate patterns and range of attachment styles.

The attachment of the gills to the stem or stipe varies, and this is one of the fundamental features used to identify mushrooms. Some gills run down the length of the stipe, while others do not touch it at all. Gills can be broadly or narrowly attached to the stipe, or they may be smoothly notched or abruptly notched before attaching. In some cases, the gills appear torn away or hanging, with evidence of attachment remaining on the stipe, usually in older specimens. Gills may also be attached and extend down the stipe, or they may form a collar or ring around it without ever meeting it.

The classification of gills is based on their attachment to the stem and their shape when viewed from the side. While most mushrooms will have an even margin or edge, some will show variations. The edges of the gills or lamellae may produce very few basidia (microscopic structures in the shape of a club, on which spores are produced) and instead be lined with cheilocystidia, which are cells with distinctive shapes and colours. If the cheilocystidia are abundant and filled with coloured pigment, the edge of the gill will have a different colour than the sides.

Additionally, gills can be classified as crowded, close, subclose, or distant, depending on the spacing between them. Crowded gills are so close together that the spaces between them may be difficult to see, while close gills are densely arranged, but with visible spaces. Subclose gills have easily visible spaces and are the most common arrangement, while distant gills are very widely separated.

Some mushrooms have false gills that are little more than folds, wrinkles or veins

Mushrooms have a fascinating way of reproducing, and their lamellae, or gills, are a key part of this. The gills are the papery hymenophore ribs found under the cap of some mushroom species, most often agarics. They are used by the mushrooms as a means of spore dispersal and are important for species identification.

While most mushrooms have gills, some have false gills that are little more than folds, wrinkles, or veins. These false gills are found in certain genera of chanterelles, including Cantharellus and Craterellus, and also in the genus Gomphus. These false gills are not separate features that can be individually picked off but rather appear as melted folds on the underside of the mushroom. They are distinguished from true gills because the structure of the fertile surface, or hymenium, continues uninterrupted over the gill edge.

False gills can be identified by their forking appearance, and they may fool those who are unfamiliar with mushrooms. It is important to learn to distinguish true from false gills if attempting to pick chanterelles, as some mushrooms with true gills may be poisonous.

The presence of gills in mushrooms is an adaptation that allows for an increased surface area, which in turn increases the potential for spore production and dispersal. This is why gills are such an important feature in the identification of mushrooms.

Microscopic features of gills, such as cheilocystidia, can be important for species identification

In mycology, a lamella (plural: lamellae), or gill, is a papery hymenophore rib under the cap of some mushroom species, most often agarics. The gills are used by the mushrooms as a means of spore dispersal and are important for species identification. The attachment of the gills to the stem is classified based on the shape of the gills when viewed from the side, while colour, crowding, and the shape of individual gills can also be important features.

Gills can have distinctive microscopic or macroscopic features. For example, the microscopic anatomy of mushrooms can be important for species identification. While most mushrooms will have an even margin or edge, some will show interesting variations. In many genera, the edges of the lamellae produce very few basidia and are instead lined with cheilocystidia, cells with distinctive shapes and colours. Cheilocystidia are cystidia that appear on the gills of mushrooms. Cystidia are sterile cells that appear on the outer surfaces of many fungi. If the cheilocystidia are abundant and filled with a coloured pigment, the edge of the gill itself will have a different colour than the sides.

The presence of gills represents a clever adaptation that allows many fungi to expand their spore-producing surfaces. By comparing the total surface area of all the gills of a mushroom (which includes both sides) to the surface area of a single, flat surface the size of the mushroom’s cap, we can see how gills greatly increase the potential for spore production and dispersal.

Additionally, the microscopic features of gills can be important for species identification. For example, the gill trama, which refers to the central part of the gills where filamentous hyphae are aligned into four basic patterns, can be observed at a lower magnification and help identify the genus when used in combination with spore colour, gill attachment, and the type of cap cuticle.

Frequently asked questions