

NATURAL ORDERS te 
vittie, are found within the secondary ridges. The seed 18 
often united with the wall of the ovary; the embryo is very 
small, the greater part of the seed being filled with endosperm, 
which does not contain starch but oil. The shape of the 
-endosperm—as, for instance, whether flat on the ventral side, or 
concave, or grooved—helps to determine the genus. 
In identifying the genera the first essential 1s to examine 
the fruit carefully, noting its shape, the number of ridges and 
oil-ducts, and the shape of the endosperm. Then the form of 
the umbel, the structure of the calyx and corolla, are taken into 
consideration, and lastly the involucres ; the involucre belong- | 
ing to the compound umbel is called the general involucre, 
whilst those beneath the simple umbels are said to be partial ; 
the presence or absence of ‘general ” and “partial” involucres 
should be noted. 
Marsh Pennywort (Hydrocotyle) is a water- 
plant creeping along the wet mud of bogs or lakes 
or floating in water. Unlike most of the Umbellifere, it has 
entire leaves and minute white flowers in simple, not com- 
Genera. 
pound, umbels. 
Astrantia has an involucre composed of bracts of a purplish 
pink colour. The flowers ° 
are small, and usually — 
either staminate or pis- oe 
tillate, and the inflores- | CECA 
cence apparently consists 
of simple umbels, which 
are, however, cymose. 
This is well seen in 
Wood Sanicle, where the 
flowers are on very short 
stalks, and form clearly 
two-sided cymes, not an 

Fig. 89.—FLowER OF ASTRANTIA. 
umbel. The fruit of b, bracts forming coloured involucre. 
Wood Sanicle is round 
and covered with hooked bristles, which no doubt aid in 
its dispersion; there 1s no carpophore. The leaves are 
