Carbon dioxide requirements for phytochrome action in photoperiodism and seed germination.

The effect of interrupting darkness with red light in the presence or absence of 0.03% CO(2) was studied in relation to flowering of Xanthium pennsylvanicum and germination of light-sensitive lettuce seeds. The results indicate that CO(2) is essential for red light to be effective in either process.

Photosynthesis: action spectra for leaves in normal and low oxygen.

The action spectrum of apparent photosynthesis for attached radish (Raphanus sativus L. var. Early Scarlet Globe) and corn (Zea mays L.

Photosynthesis: Temperate and Tropical Characteristics within a Single Grass Genus.

Leaves of two subgenera of Panicum differ in photosynthetic physiology and bundle sheath characteristics. Species of the subgenus Eupanicum, like other tropical grasses, had high phosphoenolpyruvate carboxylase (E.C.