NATURAL ORDERS. lxxix 
LXVI. Santalacese. Perianth-lobes valvate. Ovary inferior, 1-celled 
with.2 or 3 pendulous ovules. Spike simple, 
LXVII. Aristolochiaces. Perianth irregular, or 3-lobed. Stamens 6 or 
12. Ovary inferior, 3- or 6-celled, with numerous ovules. 
LXVIII. Euphorbiacee. Flower unisexual. Fruit separating into 3 
(rarely 2 or more) carpels, leaving a persistent axis, each carpel containing 
one or two pendulous seeds. . 
LXIX. Empetracee. Differs from Euphorbiacec in the ovules and seeds 
erect. | 
LXX. Ceratophyllum and Callitriche. Anomalous aquatic genera. 
Perianth none. Ovary with 1 or 4 cells, and one seed in each. 
LXXI. Utricacesee. Flowers unisexual, small and green. Stamens 
opposite the perianth-divisions (usually 4), Ovary free, with a single 
ovule, and 2 (rarely 1) styles or stigmas. . 
LXXII, Ulmacez. Trees. Flowers often bisexual, the stamens opposite 
the lobes. Ovary free, 2-celled, with one erect ovule in each cell. 
LXXIII, Amentacez. Trees or shrubs. Flowers unisexual, the males 
in catkins with an imperfect perianth, or none at all. Fruit of the females 
one-celled. 
LXXIV. Conifere, Trees or shrubs with stiff or scale-like leaves. 
Flowers unisexual, the males in catkins without perianth. Ovules and 
seeds in the females not enclosed in any ovary or pericarp. 
CLASS II.—MONOCOTYLEDONS, 
In germination the plumule is developed from a sheath-like cavity on 
one side of the embryo. | 
* Perianth none, or of 4 small sepals or bracts. 
LXXV. Typhaces. Flowers unisexual, intermixed with bracts in dense 
heads or spikes. Fruit a dry nut. 
LXXVI. Aroidez. Flowers unisexual, often intermixed with bracts, in 
dense heads or spikes, mostly ina spatha. Fruits usually succulent. 
LXXVII. Lemnacez. No distinct stem. Flowers (very scarce) on the 
edge of the small leaf-like floating fronds. 
LXXVIII. Naiades. Floating or submerged plants. Flowers distinct, 
or in loose spikes. Stamens 1, 2, or 4. Ovaries 1, 2, or 4. 
*& Perianth wholly or partially petal-like. Ovary apocarpous. 
LXXIX, Alismaceze ; the only British family of the group. 
*k* Perianth wholly or partially petal-like. Ovary inferior. 
LXXX. Hydrocharidessn. Floating or submerged plants. Flowers 
usually unisexual. Perianth regular, with a slender tube. 
LXXXI. Orchidaceze. Perianth very irregular. Anther 2-celled, com- 
bined with the style in an axile column. 
LXXXII, Iridez. Like the Amaryllis family, but stamens 3. Leaves 
often in two opposite rows. 
LXXXIII. Amaryllidee. Terrestrial plants. Perianth of 6 divisions. 
Stamens 6. 
