Monographs Details: Psidium riparium Mart. ex DC.
Authority: Maguire, Bassett. 1969. The botany of the Guayana Highland-part VIII. Mem. New York Bot. Gard. 18: 1-290.
Description:Distribution and Ecology - BRAZIL. Without locahty, Martius (M, type). Para: "In vicinibus Santarem,"Spruce 316 ["Myrcia (9)"] (M, type of P paraense; C G E , G, K, M I C H , N Y , isotypes);Tucuruy, praia Niteroi, 10 July 1949 (bud). Black 8035 (MICH; a formwith long peduncles, long petioles, dense pubescence); Igarape Remansinho, RioTocantins, 8 Sep 1948 (imm fr), Froes 23417 ( M I C H ) ; "Para, Siber [sic]" (BR,annotated by Berg, type of P sieberianum ß robustum Berg); without name of collectoror locahty (BR, annotated by Berg, type of P. sieberianum a gracile Berg);Fl. Tapajoz, Santarem, Spruce 393 (P); Santarem, Riedel 1571 (K). Matto Grosso:5. Moore 624 (BM, type of P insulincola; N Y , isotype); Cuyaba, Aug? 1892 (fl),Kuntze sn (NY, holotype of Myrtus thyrsodea); Serra do Roncador, road betweenChavantina and Carapu, 27 Sep 1964 (imm fr). Prance & Silva 59145 (MICH).Goias: Rio Maranhao, Pohl (W, lectotype of P. maranhense).
Psidium paraense Berg, Mart. Fl. Bras. 14(1): 386. 1857.
Psidium maranhense Berg, Mart. FI. Bras. 14(1): 386. 1857.
Psidium sieberianum Berg, Mart. Fl. Bras. 14(1): 387. 1857.
Psidium insulincola S. Moore, Trans. Linn. Soc. IL 4: 353. 1895.
Myrtus thyrsodea O. Kuntze, Rev. Gen. 3(2): 92. 1898.
Psidium thyrsodeum (O. Kuntze) K. Schum., Just Bot. Jahresb. 26(l): 359. 1900.
Apparently all the above names pertain to the same taxon. Individual specimens
differ in density of pubescence, and in length of peduncles and petioles. The leaves
are sessile or essentially so in the types of Psidium riparium (cf Field Mus. neg. 19722!,
photo of type at M ) , P maranhense (Field Mus. neg. 31426), P paraense, and P
insulincola; in P. thyrsodeum the petioles are up to 4 m m long, and in P. sieberianum
they are considerably longer. In some modern specimens referred to P. sieberianum
they may be as much as 15 m m long. The leaves in almost ah specimens are cordate
at base, but in forms with long petioles the blades may be rounded at base and
unequally decurrent upon the petioles.
In the original material of P. paraense the racemes usuahy bear 1 short-pedunculate
flower at a node, and the peduncles are 2-4 m m long; in all other specimens examined,
the peduncles are longer, 1-2.5 cm long, and often 3-flowered.
Branchlets and inflorescence (except the coroha) are consistently hirsute. I do
not find any differences in type of pubescence or in patterns of distribution of the
hairs, except that in the less strongly pubescent individuals the foliar hairs are confined
to the midvein on the upper surface, whereas in the most pubescent plants the
hairs may extend onto the petioles and leaf-surfaces.
In other respects all the specimens are alike to the minutest details, and I believe
the variations noted above are not taxonomically important unless it can be shown
that they are correlated with some other variables
As thus broadly delimited, Psidium riparium ranges widely south' of the Amazon,
approaching the mouth of that stream from the south, but apparently not crossing
it to the north. In the protologue the type-locality of P. riparium was given merely
as "in Brasilia ad fluminum ripas." The type, a Martius specimen at M , annotated
by de Candolle, bears the label by Martius, "in ripa flum. cum Asclepiade vicinale."
If this is the same Asclepias vicinale that was ultimately published (as a synonym, in
Mart. Fl. Bras. 6(4): 236. 1885), the type-locahty is on the Rio S. Francisco near
Joazeiro, that is, in Bahia.
Distribution:Brazil South America