Closterium pronum f. brevius
Closterium pronum f. hyalina
Closterium pronum f. sigmoideum
Closterium pronum var. acutum
Closterium pronum var. brevius
(tree size 1)
Closterium pronum var. fresenii
Closterium pronum var. pronum
Closterium pronum var. raphidioideum
Closterium pronum f. brebissonii
Closterium pronum f. hylina
Closterium pronum f. plurilocellata
Closterium pronum f. pritshardianum
Closterium pronum f. tenerrimum