Chocolate Milky vs Common Wall Cress

Lactarius lignyotus compared with Arabidopsis thaliana

Key Differences

• Chocolate Milky is Endangered while Common Wall Cress is Least Concern.

Taxonomic Classification

Rank	Chocolate Milky	Common Wall Cress
Kingdom	Fungi (Fungi)	Plantae (Plants)
Phylum	Basidiomycota (Club Fungi)	Magnoliophyta (Flowering Plants)
Class	Agaricomycetes (Mushrooms)	Magnoliopsida (Dicots)
Order	Russulales (Russulales)	Brassicales (Brassicales)
Family	Russulaceae	Brassicaceae
Genus	Lactarius	Arabidopsis
Species	Lactarius lignyotus	Arabidopsis thaliana

Conservation Status

Chocolate Milky

EN — Endangered

Common Wall Cress

LC — Least Concern

Physical Characteristics

Attribute	Chocolate Milky	Common Wall Cress
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chocolate Milky

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Asia (Taiwan), Europe (4 countries), and North America (United States). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Wall Cress

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Africa (South Africa), Asia (Japan, Taiwan), Europe (11 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (Brazil, Chile).

Chocolate Milky

The Chocolate Milky (Lactarius lignyotus) is a medium-sized ectomycorrhizal mushroom in the family Russulaceae, found in coniferous and mixed forests across Europe, North America, and temperate Asia. Like all members of the genus Lactarius, it exudes a milky latex when the flesh is broken — in L. lignyotus, this latex is white and acrid, contributing to the genus's widespread edibility variation. The fruiting body features a distinctive dark chocolate-brown to sooty-brown, velvety cap with a central boss (umbo), similarly coloured gills, and a dark brown stipe, making it relatively recognisable among forest mushrooms. It grows in close association with spruce (Picea) and fir (Abies) trees, forming ectomycorrhizal symbioses in which the fungal mycelium envelopes root tips and exchanges mineral nutrients for plant photosynthates, a relationship fundamental to the health of boreal and montane conifer forests. The IUCN classifies the chocolate milky as Endangered in certain regional assessments, reflecting declines in suitable habitat quality linked to changes in forest management, nitrogen deposition from atmospheric pollution, and climate change affecting the timing and abundance of fruiting. Accurate population monitoring of ectomycorrhizal fungi is challenging given that the fungal organism itself is largely subterranean, visible only when fruiting.

Common Wall Cress

<em>Arabidopsis thaliana</em>, commonly known as common wall cress or thale cress, is a small annual flowering plant in the family Brassicaceae native to Eurasia and Africa, and now naturalized in North America, Australia, and other temperate regions worldwide. The species has become one of the most important model organisms in plant biology and genetics, owing to its small genome size, short generation time of approximately six weeks, prolific seed production, and ease of laboratory cultivation. <em>Arabidopsis thaliana</em> was the first plant to have its complete genome sequenced, in 2000, revolutionizing our understanding of plant molecular biology, development, and physiology. In nature, it typically grows in rocky outcrops, disturbed sandy soils, walls, roadsides, and waste ground, tolerating poor nutrient conditions and a wide range of climates. The plant produces a basal rosette of small ovate leaves, followed by an erect flowering stem bearing tiny white four-petaled flowers and slender silique seed pods. Despite its modest appearance, <em>Arabidopsis thaliana</em> has facilitated thousands of scientific discoveries in plant genetics, epigenetics, and stress responses. The species is currently assessed as Least Concern by the IUCN. Biological traits such as average lifespan, plant height up to 30 centimeters, and seed output are well-characterized in laboratory settings.

Shared Countries

Both species can be found in 6 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇹🇼 Taiwan 🇺🇸 United States