Monographs Details: Palicourea elliptica Kunth
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Discussion:

Psychotria circinata H. & B. ex R. & S., Syst. Veg. 5: 190. 1819.

Palicourea circinata (H. & B.) Standi., Field Mus. Publ. Bot. 7: 464. 1931.

I have examined a specimen of the type collection from the Paris herbarium of Palicourea elliptica. Inasmuch as the taxon has not been fully described, the following description is offered: Caules subobtusiuscule quadrangulares moderatim adpresso-puberulentes; stipulis 5-9 mm longis in vaginam breviter puberulentam 3-5 mm longam connatis, vaginis in lobos ovato-oblongos obtusos 2-4 mm longos valde ciliatos striatos extus glabros desinentibus; foliorum laminis late suborbiculari-ovatis apice abrupte acutis basi late rotundatis 7-7.2 × 4.7-5.2 cm supra glabris subtus irregulariter adpresso-villosulis, nervis lateralibus utroque latere 10-12 valde divaricatis secus margines arcuato-curvatis; inflorescentia anguste pyramidali 8-12 × 4-5 cm, axibus sparse pilosulis, rhachidi pilosula; bracteis lanceolato-oblongis acutis 4.5 × 1 mm ciliatis; pedicellis 1-2 mm longis; pedunculo 1.7-3 cm longo minute adpresso-puberu-lenti; calyce hypanthioque 2-2.5 mm longo, hypanthio 1-1.2 mm longo glabro; calycis lobis ovato-oblongis obtusis vel rotundatis 0.6-0.7 × 0.5 mm ciliolatis; corolla in alabastro superne puberula ceterum glabra.

This taxon may eventually be considered as identical with either P. perquadrangularis var pubens or var guayanensis. With the latter varieties and with the P. perquadrangularis group in general, it possesses in common the following characters: (1) quadrangular stems and rachis of inflorescence; (2) many-flowered, narrowly pyramidal, subelongated inflorescence with branched lateral axes; (3) relatively large calyx and hypanthium with the constricted portion at the base of the calyx narrower than the calyx itself; (4) deeply lobed calyx with ciliate lobes; (5) glabrous exterior of the corolla except for puberulous apex and lobes; and (6) similar stipular lobes and sheath.

Conversely, the following characters found in P. elliptica are at variance with those normally occurring in P. perquadrangularis-. (1) 10-12 pairs of lateral nerves instead of 15-25; (2) leaf blades broadly suborbicular-ovate instead of lanceolate, oblong-elliptic, or elliptic-lanceolate, and; (3) leaf blades broadly rounded at base instead of narrowed or acute. However, the following specimens, assigned to the P. perquadrangularis group, indicate definite similarities to those mentioned for P. elliptica: Steyermark 98940 from Estado Falcon, referred to var perquadrangularis, has reduced leaves with only 12 pairs of nerves; Steyermark 74970, assigned to var guayanensis, has some of the leaf blades rounded at the base, as well as showing some leaves of a more suborbicular shape. This last collection would appear to be the closest match for P. elliptica, differing only in the greater number of lateral nerves of the leaf blades and in having a completely glabrous corolla. With this evidence at hand, it may be that P. elliptica represents merely a rarely collected rounded leaved form with rounded bases and fewer lateral nerves. If this is eventually found to be the case, then P. perquadrangularis Wernh. would be placed in synonymy under P. elliptica.