Hydropus marginellus is a small to medium-sized agaric fungus with a bell-shaped to convex cap, typically 1-4 cm in diameter, and a slender stem. The cap is often tan to brown with a distinctive darker brown margin. It grows in clusters or scattered on soil, moss, or decaying wood in moist environments. In East and Central Texas, Hydropus marginellus has been found in wooded areas, particularly under oak, pine, and cedar trees, during the spring and fall months when moisture is plentiful. The fungus is relatively rare in the region, but can be locally abundant in suitable habitats.
Small mushrooms Hydropus marginellus near a rotting pine on Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, September 30, 2018 Lone Star Hiking Trail, Montgomery, TX 77356, USA
Masses of mushrooms Hydropus marginellus om pine litter on Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, September 30, 2018 Lone Star Hiking Trail, Montgomery, TX 77356, USA
Close up of mushrooms Hydropus marginellus on Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, September 30, 2018 Lone Star Hiking Trail, Montgomery, TX 77356, USA
Small mushrooms Hydropus marginellus on a wet rotting pine on Winters Bayou Trail in Sam Houston National Forest. Cleveland, Texas, October 16, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, 77328, United States
Small mushrooms Hydropus marginellus on a wet pine log on Winters Bayou Trail in Sam Houston National Forest. Cleveland, Texas, October 16, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, 77328, United States
Side view of small mushrooms Hydropus marginellus on a wet rotting pine on Winters Bayou Trail in Sam Houston National Forest. Cleveland, Texas, October 16, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, 77328, United States
Close-up of small mushrooms Hydropus marginellus on a wet rotting pine on Winters Bayou Trail in Sam Houston National Forest. Cleveland, Texas, October 16, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, 77328, United States
Small mushrooms Hydropus marginellus on wet rotten pine log on Sand Branch Loop Trail in Sam Houston National Forest near Montgomery. Texas, September 10, 2022 Lone Star Hiking Trail, Montgomery County, Texas, 77873, United States
Masses of small mushrooms Hydropus marginellus on wet rotten pine log on Sand Branch Loop Trail in Sam Houston National Forest near Montgomery. Texas, September 10, 2022 Lone Star Hiking Trail, Montgomery County, Texas, 77873, United States
Mushrooms Hydropus marginellus on wet rotten pine wood on Sand Branch Loop Trail in Sam Houston National Forest near Montgomery. Texas, September 10, 2022 Lone Star Hiking Trail, Montgomery County, Texas, 77873, United States
Spores of mushrooms Hydropus marginellus on wet rotten pine wood, from Sand Branch Loop Trail in Sam Houston National Forest near Montgomery. Texas, September 10, 2022
AI-generated summary of observations
Observations of the fungus Hydropus marginellus in East and Central Texas revealed that it typically grows on rotting pine trees or logs. On Little Lake Creek Loop Trail in Richards, Texas, masses of small mushrooms were found on pine litter in September 2018. Similar sightings occurred on Winters Bayou Trail in Cleveland, Texas, in October 2021, where small mushrooms grew on wet rotting pines and pine logs. In September 2022, on Sand Branch Loop Trail near Montgomery, Texas, small mushrooms and masses of them were found on wet rotten pine logs and wood. Close-up observations showed the distinctive features of the fungus, and spores were also collected from the site. The sightings suggest that Hydropus marginellus thrives in moist environments with abundant rotting pine material. Multiple locations within Sam Houston National Forest provided suitable habitats for the fungus.