REPRODUCTIVE TISSUES 133 
stored chiefly in the medullary rays during the previous season. 
For water storage some plants have special tissues, while others 
like the Cacti store it throughout the plant body. 
Secretory Tissues. — Secretory tissues, although not so essential 
and no so common among plants as the other tissues discussed, 
perform an important function in some cases. Most showy 
flowers have secreting tissues, known as necta glands, located at 
the base of the corolla or calyx. (Fig.121.) These glands secrete 
the nectar, which, by attracting insects, aids in securing cross- 
pollination. Furthermore, honey is made from nectar, and the 
value of a plant as a bee-plant depends upon the amount and qual- 
ity of nectar secreted by its nectar glands. On the leaves, stems, 
or fruits of many plants, such 
as Mints, Oranges, Lemons, etc., 
there are glands whose secre- 
tions give the plan: a peculiar 
fragrance. In he stems and 
leaves of Conifers occur long 
tubes or ducts, known as resin 
ducts, which are lined with secre- 
tory cells that secrete resin from 
which pine tar, rosin, turpen- 
tine, and other valuable prod- 
ucts are made. Much lke the 
Fic. 121.— A Buckwheat flower 
resin ducts are the milk or lac- 
tiferous vessels of the Milkweeds 
(Asclepiadaceae), Spurges (Eu- 
with sepals removed from one side 
to show the nectar glands (n). After 
H. Miller. 
phorbiaceae), Dogbanes Apocynaceae), and other plant families 
where milk-like secretions occur. There are numerous secretions 
many of which, however, are secreted by cells in which secreting 
is not the special function. 
Reproductive Tissues. — Reproductive structures are of two 
kinds, sexual and asexual. Any portion of a plant, as a bud, 
tuber, stem, or root which may function in producing new plants, 
is regarded as an asexual reproductive structure. Some plants, 
as Irish Potatoes, Sweet Potatoes, and Strawberries illustrate, 
are quite generally propagated asexually. 
In the higher plants the sexual reproductive tissues are those 
of the flower, and more especially those of the stamens and pistils 
with which the student is familiar. Although the eggs and sperms 
