Monographs Details: Psychotria guadalupensis (DC.) R.A.Howard
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Discussion:

Loranthus guadalupensis DC., Prodr. 4: 294. 1830.

Viscoides pendulum Jacq., Select. Amer. 73. pl. 51. 1. 1763.

Psychotria parasitica Sw., Prodr. 44. 1788; Fl. Ind. Occ. 1: 408. 1797, nomen illegit.

Loranthus portoricensis DC., Prodr. 4: 293. 1830, not Psychotria portoricensis DC. 4: 515. 1830.

Uragoga grosourdieana Baill., Adansonia 12: 227, 328. 1876-9.

Mapouria parasitica K. Sch. in Engler, Pflanzenfam. 4: 112. 1891.

Uragoga parasitica Maza, Anal. Soc. Esp. Nat. II. 3: 293. 1894.

Psychotria pendula (Jacq.) Urb., Symb. Ant. 1: 445. 1900, not Hooker, Fl. Brit. Ind. 3: 164. 1880.

Loranthus peduncularis Spreng, in herb. Baill., not Jacq.

Loranthus brasiliensis Spreng, in herb. Balb. Sp. DC. 1830, not Desv.

Howard (Jour. Arnold Arb. 47: 139. 1966) has shown that the name Loranthus guadalupensis DC. must be adopted as the basionym of the next available epithet for the species passing as Psychotria parasitica and P. pendula, since Swartz in publishing Psychotria parasitica (1788) created an illegitimate name when he cited Viscoides pendulum Jacq. in synonymy. Standley was not aware of this difficulty, apparently, as he used Psychotria parasitica Sw. instead of P. pendula (Jacq.) Urb., stating that P. pendula (Jacq.) Urb. of 1900 publication date was invalidated by Hooker’s previous publication of P. pendula in 1880.

Howard has placed together all the variations published by Urban into one variable species without recognition of any varieties or subspecies. However, a study of these variations would indicate that differences do exist between at least some of them and should merit recognition. For example, the variation in Trinidad and Tobago, as well as Venezuela, assigned by Urban to P. pendula subsp trinitensis Urb. differs from P. pendula subsp grosourdyana in the conspicuously papillate-puberulent external surface of the corollas, calyx, and hypanthium, very short, shallowly triangular calyx lobes, ciliolate bracts of the inflorescence, the large leaves, and long peduncles supporting large, many-flowered inflorescences. In contrast, subsp grosourdyana has glabrous external surfaces of corollas, glabrous calyx, hypanthium, and bracts of the inflorescence, smaller leaves, shorter peduncles, and smaller, fewer-flowered inflorescences.

Other differences are apparent between specimens from Cuba of P. pendula subsp tetrapyrena. In material referred by Urban to P. pendula subsp Pachyphylla the corollas are longer than those from Puerto Rico referred by Urban to P. pendula subsp grosourdyana. Moreover, the Venezuelan material shows shorter calyces and hypanthia as well as longer inflorescences than the corresponding related West Indian material of subsp grosourdyana. Endemic species also enter into this complex of variation. The Guayana Highlands have produced an endemic species found in the Merumé Mountains of British Guiana with reduced, epedunculate or nearly epedunculate, few-flowered inflorescences, and small, rounded or obtuse leaves, and another endemic species occurs in adjacent southeastern Venezuela with winged pedicels, calyces, and hypanthia, combined with a strongly pectinate-ciliolate bordered calyx. These are treated in the following portions of the text below.