THE REPRODUCTIVE SYSTEM 349 
said to be apetalous... When as in peonies the flowers have 
calyx, corolla, stamens, and pistils, they are described as 
- complete. 
Many of the crowfoot family have the calyx petaloid, as 
In marsh-marigolds, anemonies, clematises, Christmas roses, 
fennel-flowers, baneberries, columbines, and monkshoods. 
In mouse-tails each of the sepals develops near the base a 
tubular pouch or spur (Fig. 285). 
Most commonly, the sepals, at least in the bud, overlap 
at the edges in such a way that some are wholly inside and 
some wholly outside, as shown in Figs. 282, 284. The sepals 
are then said to be imbricate,? and the same term applies to 
petals or similar organs thus overlapping. When the parts 
touch at the edges without overlapping, as for example the 
sepals of clematis (Fig. 290) they are valvate.s The arrange- 
ment of floral parts in the bud is called their estivation; + of 
leaves, their vernation.® 
_ Almost all the flowers of the family have the parts of each 
whorl alike; that is, the carpels of a flower are repetitions 
of one another, likewise the stamens, the petals, and the 
sepals when present. Such flowers are called regular. A 
few of the family have irregular flowers, as for example the 
monkshood (Fig. 178) so called from the peculiar cowl-like 
form of one of the sepals which is larger than the others and 
partially enwraps them. The hood covers also a pair of 
staminodal nectaries. The stamens with anthers and the 
gynoecium are regular. 
The stem part of the flower is called the torus * or receptacle. 
It represents the continuation of the flower-stalk or peduncle 
upon which the floral leaves grow. It is customary to speak 
of the way in which an organ is attached to its support as 
its insertion, or to say that’the organ is inserted upon what- 
ever bears it. Thus we say that the androecium and calyx 
1 A-pet’al-ous < Gr. a, without, petalon, petal. 
2 Im’-bri-cate < L. imbricatus, overlapping like roof-tiles. 
3 Val’-vate < L. valve, folding doors. 
4 JXs’-ti-va-tion < L. estivus, of the summer. 
5 Ver’-na-tion < L. vernus, of the spring. 
6 To’-rus < L. torus, a swelling, as being the swollen end of the floral 
axis. 
