C. rubra may refer to:
Canna rubra, a garden plant Cephalanthera rubra, the red helleborine, an orchid species found in Europe, north Africa and parts of Asia Chionochloa rubra, the red tussock, a plant species endemic to New Zealand Clathrina rubra, a sponge species Claytonia rubra, the redstem springbeauty, a wildflower species Crax rubra, the great curassow, a large black pheasant-like bird species