FLOKAl. CALENDAR. 



611 



tlie reach of frost, to prolong t]ieir bloom. A 

 few heaths, staticc, and pehvrgoniunis still in 

 bloom. In the stove, vinea, stapelia, i-omantliera, 

 and a few others. The increasing coolness of 

 the weather conduces to the retreat of a consi- 

 derable number of insects. 



Flies of various species, and the cristalis 

 tenax, which much resembles a drone bee, are 

 very abundant in sunny days upon the flowers 

 of the autumnal flowering conipositie. 



November and December. — The remains of the 

 plants of last month in greater or less beauty, 

 according to the weather, and perhaps a few 

 plants unnaturally in bloom. In mild winters 

 stocks of several sorts, larkspurs, violets, India 

 pinks, pot marigolds, polj'anthuses, primroses, 

 gentians, monthly i-oses,yellowamary His, daisies, 

 and various other plants. In the shrubbery, 

 clematis calycinn, and perhaps a few plants 

 unnaturally in bloom. In the greenhouse, dry- 

 andria, erica, lantana, and camellias, about the 

 middle of December. In the stove, all the spe- 

 cies of strelitzia ; also stapelias, amarillis, aletris, 

 and one or two other bull)s. From the forcing 

 department, hyacinths, Persian iris, and other 

 bulbs, monthly roses, the Provence rose, and 

 other shrubs and flowers. 



The subjoined table, drawn up by Linnseus, 

 shows the diurnal expansion of the corollas of 

 several species of flowers. 



nOROLOGIUM FLOR^, 



OR A TABLE OF THE HOURS AT WHICH CKIvTAIN PLANTS 



EXPAND AND SHUT, AT UPSAL, IN THE COtll DEGREE 



OF NORTH LAT. 



CHAP. LV. 



NATURAL FAMILIES OF DICOTYLEDONOUS PLANTS. 



In chapter xxv. we gave a summary of the 

 natural families forming the second great divi- 

 sion of plants, the monocotyledonous; in this 

 we shall enumerate the families composing the 

 third or dicotyledonous division. 



This division, as already mentioned, compre- 

 hends all those plants whose embryo has two 

 seed-lobes, or cotyledons, and comprehends the 

 greater number of flowering trees and shrubs, as 

 well as a great proportion of other flowering 

 herbaceous plants. 



In dicotyledonous plants, the stem is com- 

 posed internally of concentric layers, or circles; 

 the veins of the leaves are branched laterally; 

 there is generally both a calyx and corolla, and 

 two cotyledons in the embryo. In a single 

 family — the coniferie, these cotyledons exceed 

 two. 



AmsTOLOCHiiE, Jussieu. This family is com- 

 posed of only two genera, aristolochia and 

 asarum. It consists of herbaceous, or frutescent 

 and twining plants, bearing alternate, entire 

 leaves, and axillar flowers. Their calyx is 

 regular, with three valvar divisions, or irregular, 

 tubular, and forming a lip of very diversified 

 figure. The stamina, ten or twelve in number, 

 are inserted upon the ovary. They are some- 

 times free and distinct, sometimes intimately 

 united with the stj'le and stigma, and thus form- 

 ing a kind of nipple placed at the summit of 

 the ovary. On its lateral parts this nipple beai-s 

 the six stamina, which are bilocular, and at its 

 summit is terminated by six small lobes, which 

 may be considered as the stigmas. The fruit is 

 a capsule, or a berry with three or six cells, each 

 containing a very large number of seeds, con- 

 taining a very small embryo, placed in a flesliy 

 endospenn. 



Jussieu united to this family the genus eytinus, 

 which has become the type of a distinct family, 

 under the name of cytinem. 



The roots of the plants of this family are 

 generally tonic and stimulant, and have also been 

 employed in uterine affections. The root of 

 aristolochia serpentaria, which is aromatic, with 

 a pungent taste, has been used with success in 

 typhus. Asarabacca is diuretic, and is employed 

 as an external application for ophthalmia. 



Cytinem, Drown. The flowers are unisexual, 

 monoecious, or dioecious. The calyx is adherent, 

 rarely tree (nepenthes). Its limb has four or five 

 divisions. The stamina vary from eight to sixteen, 

 sometimes a greater number. They are mona- 

 delphous. The ovary is inferior, excepting in 

 nepenthes, with one or four cells. The seeds 

 are attached to parietal trophosperms. The stvlc 



