Cattleya walkeriana walkeriana" has been twice determined as 2"n" = 40; the diploid chromosome number of the variety "C. walkeriana" var. "princeps" has been determined as 2"n" = 80. Cattleya walkeriana Cattleya walkeriana (Walker's cattleya) is a species of orchid. It differs from most species of "Cattleya" by having inflorescences which arise from the rhizome instead of from the apex of the pseudobulb. In its native habitat (Brazilian Central Plateau) it grows as either an epiphyte or a lithophyte, sometimes in full sun. Pseudobulbs are relatively short, bulbous or fusiform, with one or two ovate leaves at the apex. Inflorescence is one-
Flower constancy could require substantial investment and switching to other flower types or species could be inefficient and consequently non-adaptive. Concentrating and feeding on one particular flower type increases the insect’s efficiency to obtain nectar from that flower type with respect to other flower types that are available. The costly information hypothesis explains flower constancy based on the fact that insects stay constant and feed on a one flower type because they know they are obtaining a reliable reward: nectar. The insect therefore does not venture to feed on other flower types because it cannot predict the amount of nectar in other