FLORA OF THE ISTHMUS OF rAXAJIA, 253 
of the leaflets. Leaflets ovato-lanceolate, remote from cue another, • Section of the base of the leaflet and 
of its articulation eUiptical. About 26 ncrvures at the widest part of the leaflet, united iuto two bundles 
at the base, but bifurcating at different distances until tliey reach the middle, or widest part, of the leaflet; 
after which they aU terminate in sharp, strong, marginal spines, which still maintain the same direction 
towards the apex. The central nervures converge towards the apex, the others being in general parallel. 
Largest leaflet 29 centimetres long, 8 c. wide. Interval between two nenTires about 3 millimetres, the 
nervures being prominent on the under surface of the leaflet, with a corresponding depression on the upper 
surface, which causes the parenchyma between the nervures to assume the form of an arch. This gives 
Z. Shinneri au extraordinary appearance, by which, and by the small number and gi-eat size of its leaflets, 
it is distinguished in a very marked manlier from every other species. Colour of the leaves bright green 
and glistening. Vernafio}i.~The young leaT rises quite erect. The stalk increases rapidly, so that, when 
two months old, it is covered with a short, soft, whitish down, muricate, the nascent spines being white, 
soft, and blunt, irregularly dispersed. During this period the four pairs, of leaflets grow much more slowly ; 
they are orbicular, and folded over one another with an imbricate vernation ; the nervures downy, doubly 
dichotomous, so thick as to occupy the whole under surface of the leaflet, though distinguished by dt-pres- 
sion between them, When the young leaf has attained to about half its ultimate length, by the rapid 
elongation of the stalk, the blade takes its turn. The leaflets proceed in their growth, increasing much 
more rapidly in length than in breadth : their increase in breadth is affected by the evolution of parenchyma 
with cuticle between the nervures, and their elongation by additions to the length of the nervures ; thus 
the form of the leaflet is changed from orbicular to elliptical and lanceolate. The leaf is fully developed in 
about four mouths. This year (1854.) my plant has put up no more leaves, but it has produced four cones, 
proving it to be a male. These, like the leaves, have risen in succession, not simultaneously ; they are of 
different sizes ; they Pesemble very much the cones of Z. Glugiia, but are less exactly cylindrical, tapering 
towards the top and bottom. The cones are much smaller than those' of Z. Chigua, already described; but 
the cause of this, in my opinion, is that my plant is, comparatively speaking, a young one ; I have no doubt 
that a full-sized male plant of Z. Skiuneri would have cones as large as those of Z Chigua. These cones 
agree with those of Z Chigua in the position of the anthers on the two sides of the scale. In concluding 
this account I would observe that my plant is admired by every one, not only on account of its rarity and 
its very marked distinctive characters, but for its handsome and striking appearance." 
915. Zamia pseiido-jyarasifica, Yates^ supra, p. 202. 
" In May 1853, 1 received from Dr. Joseph D. Hooker a leaflet of a plant from the eastern side of 
the Andes of Peru, which appears to be a Zamia, intermediate between Z. Chigua and Z Slinneri. I men- 
tion it here because it is the only Cycad^ except Z SJcinneri, in which I have seen the peculiar appearance 
produced by the prominence of the nervures on the under surface of the leaflet. The form of thfe leaflet 
is lanceolate and falcate ; length 52 c, breadth 3 c.; 18 strong nervures in the wide part of the leaflet, 
another nervure forming each margin. No appearance of teeth or spines in the margin." — James Yates. 
It was first thought by Mr. Yates that the leaflets mentioned did not belong to Z. pseudo-paraMtica, 
but I have since ascertained that they do. "Warszewicz has given two stations for this plant, Chagres, and 
the eastern side of the Andes. I have never seen this species in the Isthmus, and as it is stated only that 
the specimens were sent from Chagres, whilst in the Hookerian Herbarium they are marked "eastern side 
of the Andes," Z. pseudo-pa rasit tea must be regarded as a doubtful member of the Flora of the Isthmus 
of Panama, until additional evidence has been adduced. — ^. Seemann. 
