Studies were conducted to determine species response to low—temperature environments. Apical development was found to progress at near—freezing temperatures throughout the winter except when the plants were encased in a solid soil—ice matrix. Claytonia lanceolata and Nemophila breviflora shoots developed above the soil surface, under snow cover. In both species, chlorophyll content was inversely proportional to depth of snow cover. Spectrophotometric analysis of light penetration through snow indicated about 10% penetration through shallow layers (ca. 3.5 cm), and 0.01% through layers of 69 cm. C. lanceolata, Orogenia linearifolia, and Erythronium grandiflorum plants developed complete floral structures during the winter months, these being protected by leaves or an apical sheath (Orogenia).

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