_Pentstemon hirsutus_ (P. _pubescens_)
_Flowers_--Dull violet or lilac and white, about 1 in. long, borne in a
loose spike. Calyx 5-parted, the sharply pointed sepals overlapping;
corolla, a gradually inflated tube widening where the mouth divides
into a 2-lobed upper lip and a 3-lobed lower lip; the throat nearly
closed by hairy palate at base of lower lip; sterile fifth stamen
densely bearded for half its length; 4 anther-bearing stamens, the
anthers divergent. _Stem:_ 1 to 3 ft. high, erect, downy above.
_Leaves:_ Oblong to lance-shaped, upper ones seated on stem; lower ones
narrowed into petioles.
_Preferred Habitat_--Dry or rocky fields, thickets, and open woods.
_Flowering Season_--May-July.
_Distribution_--Ontario to Florida, Manitoba to Texas.
It is the densely bearded, yellow, fifth stamen (_pente_ = five,
_stemon_ = a stamen) which gives this flower its scientific name and its
chief interest to the structural botanist. From the fact that a blossom
has a lip in the centre of the lower half of its corolla, that an insect
must use as its landing place, comes the necessity for the pistil to
occupy a central position. Naturally, a fifth stamen would be only in
its way, an encumbrance to be banished in time. In the figwort, for
example, we have seen the fifth stamen reduced, from long sterility, to
a mere scale on the roof of the corolla tube; in other lipped flowers,
the useless organ has disappeared; but in the beard-tongue, it goes
through a series of curious curves from the upper to the under side of
the flower to get out of the way of the pistil. Yet it serves an
admirable purpose in helping close the mouth of the flower, which the
hairy lip alone could not adequately guard against pilferers. A
long-tongued bee, thrusting in his head up to his eyes only, receives
the pollen in his face. The blossom is male (staminate) in its first
stage and female (pistillate) in its second. A western species of the
beard-tongue has been selected by gardeners for hybridizing into showy
but often less charming flowers.