298 THE ORCHID REVIEW. 
which is considerably reduced, is from an excellent photograph taken by 
G. I’Anson, of Upper Clapton. 
Cypripedium xX vexillarium, Rchb. f. in Gard. Chron., 1870, p. 1373; id, 1880 i. 
780, 781, fig. 135 (‘‘selligerum” by error) ; 7@., 1887, i. p. 456, fig. 87 ; Vettch Man. Orh, 
iv., p. 100, with fig. ; Lindenia, vii., p. 45, t. 309; Orchid Album, x., t. 447. 
HYBRID ONCIDIUMS. 
THE group of Oncidiums which includes O. crispum, Forbesii, and Marshal 
lianum, to which Lindley gave the name of Tetrapetala macropetala, is one 
of the most popular in gardens, and lately it has received a considerable 
amount of attention. As regards nomenclature, the group is a rather difficult 
one. A few of the species are very well marked, though some curious inter 
mediate forms occur, and it is becoming increasingly evident that some of 
these are of hybrid origin. The Organ Mountains seem to be the heat 
quarters of the group, at least so far as our knowledge at present extends, 
and it is from this region that these intermediate forms have chiely 
appeared. ae 
As long ago as 1880 Reichenbach remarked of his O. prestans, “ there is 
little doubt of this being a mule between Oncidium dasytyle and som 
species like Gardneri,” and since then O. litum, O. Pollettianum, O. Mar 
tinii, and ©. Larkinianum have all been suspected to be of hybrid origi. 
And there are two or three others, described as species, which I believe wil 
fall into the same category, as will presently be pointed out. oa 
-The chief considerations with regard to natural hybrids generally hae 
already been pointed out under Hybrid Odontoglossums (p. 142), and a 
only be briefly recapitulated here. In the first place, they only occur whet 
species capable of inter-crossing occur in close proximity to each ~ 
Secondly, they almost invariably present a distinct combination of . 
characters of the parent species, sometimes being fairly intermedia! 
others inclining towards one or the other parent in particular 
Thirdly, as compared with the parent species, they are almost Inv* 
very rare. And, fourthly, individuals derived from the same tWO 
and even from the same seed-pod, vary considerably between be: 
especially when the parents are very diverse; thus very different | 
plants may yet have the same parentage, or, in other words, hybries © 
same parentage are generally much more variable than the 
which they are derived. 
A considerable number of species of Oncidium grow in if 
Mountains, and probably a good proportion of them could be 9Y 
together under favourable circumstances. In the particular & 
under consideration may be mentioned—O. Forbesii, O. Marsh 
