ORDER DIGYNIA. 
181 
less, modest looking plant, notwithstanding its ominous name. 
It has a small white blossom, in the parts of which, great uni- 
formity as to number may be observed ; having two stamens , a 
corolla with two petals , a calyx with two leaves , capsule with 
two cells , each of which contains two seeds. 
The symmetry of structure, observable in the plant just des- 
cribed, is seen in many flowers ; as those of two stamens often 
have the number two prevail in the other parts of the flower; 
this nufnber is frequently doubled, as in the Lilac, which has 
two stamens, and the corolla four parted. In a plant with three 
stamens, the number three or six usually prevails in the divis- 
ions of the calyx, corolla, capsule, &c. A knowledge of this 
fact will assist you in determining the class of a plant; for ex- 
ample, if you have a flower whose calyx has five or ten divis- 
ions, and the corolla the same number, you may expect, if the 
flower is a perfect one, to find either five, or ten stamens ; or if 
the divisions of the flower be two, there will generally be two, 
or four stamens ; if three, either three, or six stamens ; if four, 
either four dr eight stamens. The number five, as divisions of 
the calyx, corolla and capsule, is generally united to five or ten 
stamens, and found in the 5th and 10th classes. 
Another native plant of the second class, is the Veronica. Of 
the seventy species which this genus is said to contain, no more 
than six or eight are common to North America. The Veronica 
and the Circaea both turn black when dried ; although they do 
not add to the beauty of an herbarium, they are desirable in a 
collection of plants, as our country contains few specimens to 
illustrate the second class. 
Among the exotics of this order we find a singular plant pe- 
culiar to the East Indies, the Nyctanthes arbor tristis , or sor- 
rowful tree ;• it drops its boughs during the, day, but through 
the night they are erect and appear fresh and flourishing. 
The Olive (Olea) is common on the rocks of Palestine, and 
may now according to the accounts of travellers be found upon 
the same spot which was called, eleven centuries before the 
Christian era, the mount of Olives, or mount Olivet. 
ORDER DIGYNIA. 
In the second order of this class is the Sweet vernal grass. 
(Anthoxanthum odoralum,) which is found in blossom in May; 
this is the kind of grass which is used in this country as a sub- 
stitute for the Leghorn grass, in the manufacture of hats. The 
first hat of the kind was made a few years since by an ingen- 
Arbor tristis — Olea. 
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