Stems: stout, erect, rigid. Leaves: radical, solitary, deeply channeled, cauline narrow, convolute. Flowers: sepals lanceolate, acuminate, petals cuneate-obovate. Fruit: capsule lanceolate, attenuate, upward, seeds numerous.

The Green-banded Mariposa is a very beautiful perennial lily, with one or more flowers growing on a stiff erect stem, and the single long basal leaf being deeply channeled. The three narrow pointed sepals are purplish-green with a dark base inside, sometimes spotted and hairy, and the three broad, more or less concave petals are pale lilac with a greenish line down the centre. The gland is oblong and densely hairy. This lily grows in very dry places. Its large bulbs are considered a great delicacy by the Indians, who call them noonas.

Calochortus Lyallii, or Pale Mariposa, grows on the grassy slopes of high mountains. It has a slender stem bearing three to five flowers in an umbel, each blossom composed of three greenish-purple sepals strongly arched below, the pit thus formed being dark purple inside, and the three white, or pale yellow petals, having a purplish base and being also arched below.