(Pentstemon hirsutus; P. pubescens of Gray) Figwort family
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 shape, upper
ones seated on stem; lower ones narrowed into petioles.
Preferred Habitat - Dry or rocky fields, thickets, and open
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 center 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.
While this is the beard-tongue commonly found in the Eastern
United States, particularly southward, and one of the most
beautiful of its clan, the western species have been selected by
the gardeners for hybridizing into those more showy, but often
less charming, flowers now quite extensively cultivated. Several
varieties of these, having escaped from gardens in the East, are
locally common wild.
The LARGE-FLOWERED BEARD-TONGUE (P. grandiflorus), one of the
finest prairie species, whose lavender-blue, bell-shaped corolla
is abruptly dilated above the calyx, measures nearly two inches
long. Its sterile filament, curved over at the summit, is bearded
Handsomest of all is the COBEA BEARD-TONGUE, a native of the
Southwest, with a broadly rounded, bell-shaped corolla, hairy
without, like the leaves, but smooth within. The pale purple
blossom, delicately suffused with yellow, and pencilled with red
lines - pathfinders for the bees - has the base of its tube
creamy white. Few flowers hang from each stout clammy spike.
The more densely crowded spikes of the large SMOOTH BEARD-TONGUE
(P. glaber), a smaller blue or purple flowered, narrower-leaved
species, that shows an unusual preference for moist soil
throughout its range, is, like the other beard-tongues mentioned,
better known to the British gardener, perhaps, than to Americans,
who have yet to learn the value of many of their wild flowers
The tall FOXGLOVE BEARD-TONGUE (P. digitalis), with large, showy
white blossoms tinged with purple, the one most commonly grown in
gardens here, escapes on the slightest encouragement to run wild
again from Maine to Virginia, west to Illinois and Arkansas.
Small bees crawl into the broad tube, and butterflies drain the
nectar evidently secreted for long-tongued bees, but without
certainly transferring pollen. To insure cross-fertilization, the
flower first develops its anthers, whose saw-edges grating
against the visitors thorax, aid in sifting out the dry pollen;
and later the style, which when immature clung to the top of the
corolla, lowers its receptive stigma to oppose the bee's
entrance. Professor Robertson has frequently detected the common
wasp nipping holes with her sharp jaws in the base of the tube.
With remarkable intelligence she invariably chose to insert her
tongue at the precise spots where the nectar is stored on either
side of the sterile filament.
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