Monographs Details: Psidium guyanense Pers.
Authority: Maguire, Bassett. 1969. The botany of the Guayana Highland-part VIII. Mem. New York Bot. Gard. 18: 1-290.
Family:Myrtaceae
Scientific Name:Psidium guyanense Pers.
Description:Distribution and Ecology - V E N E Z U E L A . Bolivar: Near El Dorado, Calzeta de la Boteha, in savanna, elev100 m, 14 Apr 1957 (imm fr), Bernardi 6539 ( M I C H ) ; Altiplanicie de Nuria, E ofMiamo, elev 230-350 m, 21 Jan 1961 (imm fr), Steyermark 88641 (NY). BRITISHGUIANA. Orinduik, Ireng River, 16 Nov 1962 (fr). Forest Dept. 7818 (NY).F R E N C H GUIANA. Without locality, Richard {¥;. herb. Juss. 13845, type of Pguyanense), Richard (P, type of P. richardianum). BRAZIL. Amapa: road toAmapa, k m 108, Rio Pedrevia, 19 Jul 1962 (fr), Pires & Cavalcante 52226 (MICH).Para: "In vicinis Santarem," Spruce 825 ["Psidium (1)"], Aug 1850 (bud) (M,type of P. sprucei; C G E , N Y , isotypes); Santarem, Riedel (type of P umbrosum, atLE, not seen; Field Mus. neg. 36423, based on a presumed isotype at P ) ; Vigia, beirade campina do Caembe, 22 Jan 1950 (fr). Black 8760 ( M V M ) . Maranhao: Islandof Sao Luis, Estrado do Olho d'Agua, Feb-Mar 1939 (bud), Froes 11626 (NY).

Discussion:

Psidium fluviatile Rich, ex BCBCVrodr. S: 235. 1828.

Psidium sprucei Berg, Mart. Fl. Bras. 14(1): 396. 1857.

Psidium umbrosum Berg, Mart. Fl. Bras. 14(1): 599. 1859.

Psidium richardianum Berg, Linnaea 30: 705. 1861

Apparently all the above names pertain to the same taxon. The types of Psidium sprucei and P. umbrosum are from the same locality (Santarem, Para), and those of P guyanense and P richardianum are from French Guiana. All the specimens bear a general resemblance to thinly pubescent examples of P guineense; the young branchlets, lower leaf-surfaces and veins, peduncles, hypanthia, and calyces vary from rather densely and finely puberulent with upright hairs, to nearly glabrous; the buds are 8-12 m m long, with a smah circular apical opening.

From the limited numbers of specimens now available, it seems that this species is rather widely distributed but not especially common, from northern \'enezuela to the Guianas and eastern Brazil. Because of its close resemblance to Psidium guineense it is included here with some reservations, but it does appear to have a reasonable geographical distribution which may be that of an independently evolved taxon.

The name Psidium guyanense, as pointed out below, was applied in the Flora of Suriname (with the spelling guianense) to the glabrous plant which in the present paper is called P. persoonii. The type of P. guyanense, however, is the somewhat pubescent plant that Berg later called P sprucei, P. umbrosum and P. richardianum:

see the discussion under P. persoonii. The name P. fluviatile is based nomenclaturally upon P. guyanense, and is therefore illegitimate. Richard seems to have collected both the pubescent plant and the glabrous one, calling the former P. laurifolium and the latter P fluviatile; Persoon described the pubescent one as P guyanense and Berg the same one as P. richardianum; the identity of the actual plant studied by de Candolle is irrelevant, since he included the name "P. guianense Pers.'' in the synonymy of his P. fluviatile.

The types of Psidium sprucei and P. umbrosum are rather sparingly pubescent even for this species, whereas the original material of P. richardianum represented a somewhat more hairy form. The type of the latter, which I saw at Paris in 1965, is a weh preserved flowering specimen from the herbarium of Richard, collected in French Guiana, marked (by Richard?) "Psydium laurifolium" (as noted by Berg in the protologue), and accompanied by a long manuscript description, and sketches of the bud. An isotype, also at Paris, has been photographed (Field IVlus. neg. 36418).

The type of Psidium donianuni Berg (Mart. Fl. Bras. 14(1): 521. 1858), probably represents this same species. The specimen consists of fully mature, somewhat coriaceous leaves on a short twig; a fruit at one time formed a part of the specimen. BRAZIL. Maranhao: Without locahty, Don 102 (BR).

Distribution:Venezuela South America| Brazil South America|