Psittacanthus calyculatus

Psittacanthus calyculatus is hairless, with nearly terete branches.[3] The leaves are opposite and ovate or lanceolate, having almost no petiole, and without veins.[3] The inflorescences are terminal and in groups of three yellow to scarlet flowers which have cup-shaped bracts under them.[3]

In October or November, the fruit matures, and is eaten by a bird, who voids the seed. By November, if the defecation site is a suitable branch, the seed may have infected the host, and initial buds will start to appear.[4] Vegetative growth continues, until, four years after the initial infection, the plant flowers in November, with fruit becoming mature the following year from October to February.[4] Thus, there are some five years required for its life-cycle.[4]

Vasquez Collazo and Geils (2002) report eleven observed conifer hosts for Psittacanthus calyculatus: Abies religiosa, Pinus douglasiana, P. lawsonii, P. leiophylla, P. michoacana, P. pseudostrobus, P. teocote, P. montezumae, P. herrerai, P. pringlei, and P. rudis.[4]

At least nineteen bird species (insectivores, omnivores, and granivores) have been seen feeding on the fruits.[4]

Psittacanthus calyculatus was first described by de Candolle in 1830 as Loranthus calyculatus,[5][6] and in 1834, Don assigned it to the new genus Psittacanthus.[1][3]

Psittacanthos comes from the Greek psittakos (parrot), and the Greek anthos (flower), chosen according to Don,[3] possibly because of the bright colours. Calyculatus is the Latin for provided with a calyculus which is a cup-like structure below the calyx, formed by a whorl of bracts[7]