g._ the orange-flowered
puccoons (_Lithospermum_); but it also embraces a number of the most
troublesome weeds, among which are the hound's-tongue (_Cynoglossum_)
(Fig. 119, _A_), and the "beggar's-ticks" (_Echinospermum_), whose
prickly fruits (Fig. 119, _C_) become detached on the slightest
provocation, and adhere to whatever they touch with great tenacity.
The flowers in this family are arranged in one-sided inflorescences
which are coiled up at first and straighten as the flowers expand.

The last family (_Solaneae_) includes the nightshades (_Solanum_)
(Fig. 119, _D_), to which genus the potato (_S. tuberosum_) and the
egg-plant (_S. Melongena_) also belong. Many of the family contain a
poisonous principle, _e.g._ the deadly nightshade (_Atropa_), tobacco
(_Nicotiana_), stramonium (_Datura_), and others. Of the cultivated
plants, besides those already mentioned, the tomato (_Lycopersicum_),
and various species of _Petunia_ (Fig. 119, _H_), _Solanum_, and
_Datura_ are the commonest.

The second order of the _Anisocarpae_ consists of plants whose flowers
usually exhibit very marked, bilateral symmetry (_Zygomorphism_). From
the flower often being two-lipped (see Fig. 120), the name of the
order (_Labiatiflorae_) is derived.

Of the nine families constituting the order, all but one are
represented within our limits, but the great majority belong to two
families, the mints (_Labiatae_) and the figworts (_Scrophularineae_).
The mints are very common and easily recognizable on account of their
square stems, opposite leaves, strongly bilabiate flowers, and the
ovary splitting into four seed-like fruits (Fig. 120, _D_, _F_).

The great majority of them, too, have the surface covered with
glandular hairs secreting a strong-scented volatile oil, giving the
peculiar odor to these plants. The dead nettle (_Lamium_) (Fig. 120,
_A_) is a thoroughly typical example. The sage, mints, catnip,
thyme, lavender, etc., will recall the peculiarities of the family.

The stamens are usually four in number through the abortion of one of
them, but sometimes only two perfect stamens are present.

[Illustration: FIG. 120.--_Anisocarpous sympetalae_ (_Labiatiflorae_).
_A_, dead nettle, _Lamium_, (_Labiatae_), x 1/2. _B_, a single flower,
x 1. _C_, the stamens and pistil, x 1. _D_, cross-section of the
ovary, x 2. _E_, diagram of the flower; the position of the absent
stamen is indicated by the small circle. _F_, fruit of the co