A large family, widely distributed, chiefly tropical; ours are
perennial herbs, with milky, bitter juice; leaves toothless, usually
opposite, without stipules; flowers perfect, parts in fives; corolla
united; stamens on the corolla, as many as its lobes, alternate with
them, ovary superior, in two parts, united by a single or two-parted
style, developing into two pods; seeds often tufted with hairs. The
Greek name alludes to the superstition that these plants are poisonous
to dogs.
There are many kinds of Apocynum, with branching stems, tough fibrous
bark, and small, white or pink flowers, in clusters; calyx with pointed
teeth, its tube adhering to the ovaries by means of a thickish,
five-lobed disk; corolla bell-shaped, five-lobed, with five, small,
triangular appendages, inside the tube, opposite the lobes; stamens
with short, broad filaments and arrow-shaped anthers, slightly adhering
to the blunt, obscurely two-lobed stigma; pod slender, cylindrical;
seeds numerous, small, feathery.
[Sidenote: =Spreading Dogbane, Honey-bloom=
_Apócynum androsaemifòlium_
=White, pink
Summer
West, etc.=]
An attractive plant, from one to four feet high, with many, smooth,
widely spreading branches, purplish on one side, and smooth leaves,
rather dark green above, pale underneath, with yellowish veins. The
little flowers are white, tinged with pink, often striped with pink
inside, mainly in loose clusters at the ends of the branches, and
though not conspicuous are delicate and pretty. The pods are from two
to seven inches long. This is widely scattered in fields and open
woods, occurring in a variety of forms, and common in the East.
[Illustration: Dog-bane--Apocynum androsaemifolium.