ae et ee 
g 7 
fi 
| 2 XXXV. UMBELLIFERAE, 175 
nerves or rzbs, occasionally expanded into wings, and underneath 
or within the pericarp are often longitudinal channels, called 
vittas, filled with an oily or resinous substance. Embryo minute, 
in a horny albumen, which either fills the seed or is deeply 
furrowed or excavated on the inner face. 
A numerous family, more or less represented nearly all over the 
globe; but the species are comparatively few in high northern lati- 
tudes, as well as within the topics, their great centre being western 
Asia and the Mediterranean region. Their inflorescence, and the struc- 
ture of their flowers, distinguish them at once from all other families, 
except that of the Aralias, and these have either more than 2 styles, 
or the fruit is a berry. But the subdivision of Umbellifers into genera 
is much more difficult. Linnzus marked out several which were 
natural, but without definite characters to distinguish them; and the 
modern genera, founded upon a nice appreciation of minute differences 
in the fruit and seed, are often very artificial, or still more frequently 
reduced to single species, and as artificial as those of Cruciferw and 
Composite. ‘These minute characters are moreover in many cases very 
difficult to ascertain. I have, therefore, in the following Analytical 
Key, endeavoured to lead to the determination of the species, as far 
as possible, by more salient though less absolute characters, which may 
suffice in a great measure for the few British species, although, even for 
them, the minute variations of the fruit cannot be wholly dispensed 
with. For this purpose it is essential to have the fruit quite ripe. It 
must then be cut across, and if a horizontal slice is placed under a lens, 
the general form, the ribs and furrows of the pericarp, and the vittas, 
will clearly appear. When the fruit is described as laterally compressed, 
this slice is of an oval form, the division between the carpels being 
across the narrow diameter; where it is flattened from front to back, 
(dorsally) the division is across the broadest diameter. In Seseli and 
other genera, where the fruit is not compressed, the horizontal slice is 
orbicular. Where the albumen is furrowed, its transverse section 
assumes a more or less half-moon or kidney shape. 
1 f Leaves undivided t ‘ ‘ 2 
\ Leaves palmate or pinnate, or vari iously dissected : : i ” : is 
Leaves quite entire, grass- like or ovate. Flowers yellow . . 18. BUPLEVRUM. 
| eaves rounded, cr enate or peltate. Aquatic or marsh hens Ww ith small 
heads or whorls of flowers . ‘ . HYDROCOTYLE. 
Leaves and globular heads of flowers very pr rickly . 4 ERYNGIUM. 
| eaves and stems very thick and succulent . ; ; . 21. CRITHMUM. 
Leaves neither prickly nor fieshy . : se 4 
ue covered with prickles or bristles or hairs, or with toothed or sit nuate 
44 ° ribs ‘ ‘ ‘ . t5 
Fruit elabrous and smooth, or with entire ribs or W ines : : nt 
5 { Leaves orbicular or palmate. Umbels simple or ir regularly compound é BES 
Leaves pinnate or much dissected. Umbels usually compound : ‘ ye 
Flowers in small heads, without involucre. Fruit prickly : 2. SANICULA. 
6} Flowers in simple or irregularly compound umbels. Involucre of many 
bracts. Fruit. rough, with sinuate or toothed ribs . ‘ . 3. ASTRANTTIA. 
” { Fruit covered with bristles or prickles or hairs : , 338 
Fruit glabrous, with sinuate ribs . ‘ : : .33. CONIUM. 
8 Fruit flat, with a thick border < : ; ; . 26. TORDYLIUM. 
Fruit ovoid, not bordered , : ‘ a9 
Bracts of the involucre mostly pinnatifid 32, DAUCUS. 
