[5] Comandra is a perennial herb growing from rhizomes, often in drier or semi-sandy soils,[6] to about 8 to 34 centimetres (3+1⁄4 to 13+1⁄2 in) tall.

Growing in flat or roundish clusters, the flowers lack petals, but have five greenish-white sepals.

[7] These include: Acer, Antennaria, Aster, Betula, Carex, Solidago, Fragaria, Populus, Quercus, Rosa, Rubus, Vaccinium and some grasses.

[11] When C. umbellata is infected by the rust aeciospores from the pine host, yellow, blister-like spots bearing urediniospores appear on the leaves of the plant within 20 days.

In the following weeks, teliospores develop on brown, hairlike telia that germinate to produce basidiospores, the fungal life stage capable of infecting pines.