Helodeaster erici is a short, rhizomatous perennial herb. The scapes are often tinged purple, measuring 3-15 cm in length. They are sparse to moderately hirtellous and villous, with a few subsessile globose glands, becoming more pubescent and glandular at the base of the head and glabrate with age. The leaves are basal, oblong, and occasionally oblong-oblanceolate, measuring 0.8-1.3(-1.8) cm long and 0.2-0.45 cm wide. They are sessile and more or less clasping the stem, with 1-3 bracts per scape that are slightly larger and more leaf-like toward the base. The leaves are glabrous, sometimes sparsely hirtellous on the margins and veins, with golden or purplish hairs and occasionally a few scattered, subsessile, globose glands. The margins are serrate in the upper half, glabrous, or sparsely hirtellous. The heads are solitary, (5-)6-10 mm in diameter, and disciform. The involucral bracts are 2.5-5 mm long, with an apex usually tinged purple and sparsely hirtellous. Ray florets are inconspicuous, sometimes appearing disk-like, pistillate, white, or sometimes tinged purple, entire or deeply and asymmetrically 2-4-lobed, 0.7-1.4 mm long, with scattered, subsessile, globose glands and sometimes a few long hairs. Disk florets are perfect, with yellow corollas, (3)4(5)-lobed, 1.8-2.7 mm long, and scattered, subsessile, globose glands. The fruit is a simple, dry achene that is compressed and tapering to the apex, beakless but with a conspicuous cartilaginous ring at maturity, 1.2-1.7 mm long, with scattered, subsessile, globose glands usually near the apex. It is found in bogs beetween 1065-1550 meters.