|
ORCHID FAMILY (Orchidaceae)
Large Yellow Lady's Slipper; Whippoorwill's Shoe; Yellow Moccasin Flower
Cypripedium pubescens (C. hirsutum)
Flower--Solitary, large, showy, borne at the top of a leafy stem 1
to 2 ft. high. Sepals 3, 2 of them united, greenish or yellowish, striped
with purple or dull red, very long, narrow; 2 petals, brown, narrower,
twisting; the third an inflated sac, open at the top, 1 to 2 in. long, pale
yellow, purple lined; white hairs within; sterile stamen triangular; stigma
thick. Leaves: Oval or elliptic, pointed, 3 to 5 in. long,
parallel-nerved, sheathing.
Preferred Habitat--Moist or boggy woods and thickets; hilly
ground.
Flowering Season--May-July.
Distribution--Nova Scotia to Alabama, westward to Minnesota and
Nebraska.
Swinging outward from a leaf-clasped stem, this orchid attracts us by its
flaunted beauty and decorative form from tip to root, not less than the
aesthetic little bees for which its adornment and mechanism are so
marvellously adapted. Doubtless the heavy, oily odor is an additional
attraction to them.
These common orchids, which are not at all difficult to naturalize in a
well-drained, shady spot in the garden, should be lifted with a good ball of
earth and plenty of leaf-mould immediately after flowering.
The similar Small Yellow Lady's Slipper (C. parviflorum), a
delicately fragrant orchid about half the size of its big sister, has a
brighter yellow pouch, and occasionally its sepals and petals are purplish.
As they usually grow in the same localities, and have the same blooming
season, opportunities for comparison are not lacking. This fairer, sweeter,
little orchid roams westward as far as the State of Washington.
Moccasin Flower; Pink, Venus', or Stemless Lady's Slipper
Cypripedium acaule
Flowers--Fragrant, solitary, large, showy, drooping from end of
scape, 6 to 12 in. high. Sepals lance-shaped, spreading, greenish purple, 2
in. long or less; petals narrower and longer than sepals. Lip an inflated
sac, often more than 2 in. long, slit down the middle, and folded inwardly
above, pale magenta, veined with darker pink; upper part of interior crested
with long white hairs. Stamens united with style into unsymmetrical declined
column, bearing an anther on either side, and a dilated triangular
petal-like sterile stamen above, arching over the broad concave stigma.
Leaves: 2, from the base; elliptic, thick, 6 to 8 in. long.
Preferred Habitat--Deep, rocky, or sandy woods.
Flowering Season--May-June.
Distribution--Canada southward to North Carolina, westward to
Minnesota and Kentucky.
Because most people cannot forbear picking this exquisite flower that
seems too beautiful to be found outside a millionaire's hothouse, it is
becoming rarer every year, until the finding of one in the deep forest,
where it must now hide, has become the event of a day's walk. Once it was
the commonest of the orchids.
"Cross-fertilization," says Darwin, "results in offspring which vanquish
the offspring of self-fertilization in the struggle for existence." This has
been the motto of the orchid family for ages. No group of plants has taken
more elaborate precautions against self-pollination or developed more
elaborate and ingenious mechanism to compel insects to transfer their pollen
than this.
The fissure down the front of the Pink Lady's Slipper is not so wide but
that a bee must use some force to push against its elastic sloping sides and
enter the large banquet chamber where he finds generous entertainment
secreted among the fine white hairs in the upper part. Presently he has
feasted enough. Now one can hear him buzzing about inside, trying to find a
way out of the trap. Toward the two little gleams of light through apertures
at the end of a passage beyond the nectary hairs he at length finds his way.
Narrower and narrower grows the passage until it would seem as if he could
never struggle through; nor can he until his back has rubbed along the
sticky, overhanging stigma, which is furnished with minute, rigid, sharply
pointed papillae, all directed forward, and placed there for the express
purpose of combing out the pollen he has brought from another flower on his
back or head. The imported pollen having been safely removed, he still has
to struggle on toward freedom through one of the narrow openings, where an
anther almost blocks his way.
As he works outward, this anther, drawn downward on its hinge, plasters
his back with yellow granular pollen as a parting gift, and away he flies to
another lady's slipper to have it combed out by the sticky stigma as
described above. The smallest bees can squeeze through the passage without
paying toll. To those of the Andrena and Halictus tribe the flower is
evidently best adapted. Sometimes the largest bumblebees, either unable or
unwilling to get out by the legitimate route, bite their way to liberty.
Mutilated sacs are not uncommon. But when unable to get out by fair means,
and too bewildered to escape by foul, the large bee must sometimes perish
miserably in his gorgeous prison.
Showy, Gay, or Spring Orchis
Orchis spectabilis
Flowers--Purplish pink, of deeper and lighter shade, the lower lip
white, and thick of texture; from 3 to 6 on a spike; fragrant. Sepals
pointed, united, arching above the converging petals, and resembling a hood;
lip large, spreading, prolonged into a spur, which is largest at the tip and
as long as the twisted footstem. Stem: 4 to 12 in. high, thick,
fleshy, 5-sided. Leaves: 2, large, broadly ovate, glossy green,
silvery on underside, rising from a few scales from root. Fruit: A
sharply angled capsule, 1 in. long.
Preferred Habitat--Rich, moist woods, especially under hemlocks.
Flowering Season--April-June.
Distribution--From New Brunswick and Ontario southward to our
Southern states, westward to Nebraska.
Of the six floral leaves which every orchid, terrestrial or aerial,
possesses, one is always peculiar in form, pouch-shaped, or a cornucopia
filled with nectar, or a flaunted, fringed banner, or a broad platform for
the insect visitors to alight on. Some orchids look to imaginative eyes as
if they were masquerading in the disguise of bees, moths, frogs, birds,
butterflies. A number of these queer freaks are to be found in Europe.
Spring traps, adhesive plasters, and hair-triggers attached to explosive
shells of pollen are among the many devices by which orchids compel insects
to cross-fertilize them, these flowers as a family showing the most
marvellous mechanism adapted to their requirements from insects in the whole
floral kingdom. No other blossoms can so well afford to wear magenta, the
ugliest shade nature produces, the "lovely rosy purple" of Dutch bulb
growers.
Large, or Early, Purple-fringed Orchis
Habenaria fimbriata (H. grandiflora)
Flowers--Pink-purple and pale lilac, sometimes nearly white;
fragrant, alternate, clustered in thick, dense spikes from 3 to 15 in. long.
Upper sepal and toothed petals erect; the lip of deepest shade, 1/2 in.
long, fan-shaped, 3-parted, fringed half its length, and prolonged at base
into slender, long spur; stamen united with style into short column; 2
anther sacs slightly divergent, the hollow between them glutinous,
stigmatic. Stem: 1 to 5 ft. high, angled, twisted. Leaves:
Oval, large, sheathing the stem below; smaller, lance-shaped ones higher up
bracts above. Root: Thick, fibrous.
Preferred Habitat--Rich, moist meadows, muddy places, woods.
Flowering Season--June-August.
Distribution--New Brunswick to Ontario; southward to North
Carolina, westward to Michigan.
Because of the singular and exquisitely unerring adaptations of orchids
as a family to their insect visitors, no group of plants has greater
interest for the botanist since Darwin interpreted their marvellous
mechanism, and Gray, his instant disciple, revealed the hidden purposes of
our native American species, no less wonderfully constructed than the most
costly exotic in a millionaire's hothouse.
A glance at the spur of this orchid, one of the handsomest and most
striking of its clan, and the heavy perfume of the flower, would seem to
indicate that only a moth with a long proboscis could reach the nectar
secreted at the base of the thread-like passage. Butterflies, attracted by
the conspicuous color, sometimes hover about the showy spikes of bloom, but
it is probable that, to secure a sip, all but possibly the very largest of
them must go to the smaller Purple-fringed Orchis, whose shorter spur holds
out a certain prospect of reward; for, in these two cases, as in so many
others, the flower's welcome for an insect is in exact proportion to the
length of its visitor's tongue. Doubtless it is one of the smaller sphinx
moths, such as we see at dusk working about the evening primrose and other
flowers deep of chalice, and heavily perfumed to guide visitors to their
feast, that is the great Purple-fringed Orchid's benefactor, since the
length of its tongue is perfectly adapted to its needs. Attracted by the
showy, broad lower petal, his wings ever in rapid motion, the moth proceeds
to unroll his proboscis and drain the cup that is frequently an inch and a
half deep. Thrusting in his head, either one or both of his large,
projecting eyes are pressed against the sticky button-shaped discs to which
the pollen masses are attached by a stalk, and as he raises his head to
depart, feeling that he is caught, he gives a little jerk that detaches
them, and away he flies with these still fastened to his eyes.
Even while he is flying to another flower, that is to say, in half a
minute, the stalks of the pollen masses bend downward from the perpendicular
and slightly toward the centre, or just far enough to require the moth, in
thrusting his proboscis into the nectary, to strike the glutinous, sticky
stigma. Now, withdrawing his head, either or both of the golden clubs he
brought in with him will be left on the precise spot where they will
fertilize the flower. Sometimes, but rarely, we catch a butterfly or moth
from the smaller or larger purple orchids with a pollen mass attached to his
tongue, instead of to his eyes; this is when he does not make his entrance
from the exact centre--as in these flowers he is not obliged to do--and in
order to reach the nectary his tongue necessarily brushes against one of the
sticky anther sacs. The performance may be successfully imitated by
thrusting some blunt point about the size of a moth's head, a dull pencil or
a knitting-needle, into the flower as an insect would enter. Withdraw the
pencil, and one or both of the pollen masses will be found sticking to it,
and already automatically changing their attitude. In the case of the large,
round-leaved orchis, whose greenish-white flowers are fertilized in a
similar manner by the sphinx moth, the anther sacs converge, like little
horns; and their change of attitude while they are being carried to
fertilize another flower is quite as exquisitely exact.
White-fringed Orchis
Habenaria blephariglottis
Flowers--Pure white, fragrant, borne on a spike from 3 to 6 in.
long. Spur long, slender; oval sepals; smaller petal toothed; the oblong lip
deeply fringed. Stem: Slender, 1 to 2 ft. high. Leaves:
Lance-shaped, parallel-veined, clasping the stem; upper ones smallest.
Preferred Habitat--Peat-bogs and swamps.
Flowering Season--July-August.
Distribution--Northeastern United States and eastern Canada to
Newfoundland.
One who selfishly imagines that all the floral beauty of the earth was
created for man's sole delight will wonder why a flower so exquisitely
beautiful as this dainty little orchid should be hidden in inaccessible
peat-bogs, where overshoes and tempers get lost with deplorable frequency,
and the water-snake and bittern mock at man's intrusion of their realm by
the ease with which they move away from him. Not for man, but for the bee,
the moth, and the butterfly, are orchids where they are and what they are.
Yellow-fringed Orchis
Habenaria ciliaris
Flowers--Bright yellow or orange, borne in a showy, closely set,
oblong spike, 3 to 6 in. long. The lip of each flower copiously fringed; the
slender spur 1 to 1-1/2 in. long; similar to White-fringed Orchis (see
above); and between the two, intermediate pale yellow hybrids may be found.
Stem: Slender, leafy, 1 to 2-1/2 feet high. Leaves:
Lance-shaped, clasping.
Preferred Habitat--Moist meadows and sandy bogs.
Flowering Season---July-August.
Distribution--Vermont to Florida; Ontario to Texas.
Where this brilliant, beautiful orchid and its lovely white sister grow
together in the bog--which cannot be through a very wide range, since one is
common northward, where the other is rare, and vice versa--the
Yellow-fringed Orchis will be found blooming a few days later. In general
structure the plants closely resemble each other.
From Ontario and the Mississippi eastward, and southward to the Gulf, the
Tubercled or Small Pale Green Orchis (H. flava) lifts a spire of
inconspicuous greenish-yellow flowers, more attractive to the eye of the
structural botanist than to the aesthete. It blooms in moist places, as most
orchids do, since water with which to manufacture nectar enough to fill
their deep spurs is a prime necessity. Orchids have arrived at that pinnacle
of achievement that it is impossible for them to fertilize themselves. More
than that, some are absolutely sterile to their own pollen when it is
applied to their stigmas artificially! With insect aid, however, a single
plant has produced more than 1,000,700 seeds. No wonder, then, that as a
family, they have adopted the most marvellous blandishments and mechanism in
the whole floral kingdom to secure the visits of that special insect to
which each is adapted, and, having secured him, to compel him unwittingly to
do their bidding. In the steaming tropical jungles, where vegetation is
luxuriant to the point of suffocation, and where insect life swarms in
myriads undreamed of here, we can see the best of reasons for orchids
mounting into trees and living on air to escape strangulation on the ground,
and for donning larger and more gorgeous apparel to attract attention in the
fierce competition for insect trade waged about them. Here, where the
struggle for survival is incomparably easier, we have terrestrial orchids,
small, and quietly clad, for the most part.
Calopogon; Grass Pink
Calopogon pulchellus (Limodorum tuberosum)
Flowers--Purplish pink, 1 in. long, 3 to 15 around a long, loose
spike. Sepals and petals similar, oval, acute; the lip on upper side of
flower is broad at the summit, tapering into a claw, flexible as if hinged,
densely bearded on its face with white, yellow, and magenta hairs (Calopogon
= beautiful beard). Column below lip (ovary not twisted in this exceptional
case); sticky stigma at summit of column, and just below it a 2-celled
anther, each cell containing 2 pollen masses, the grain lightly connected by
threads. Scape: 1 to 1-1/2 ft. high, slender, naked. Leaf:
Solitary, long, grass-like, from a round bulb arising from bulb of previous
year.
Preferred Habitat--Swamps, cranberry bogs, and low meadows.
Flowering Season--June-July.
Distribution--Newfoundland to Florida, and westward to the
Mississippi.
Fortunately this lovely orchid, one of the most interesting of its highly
organized family, is far from rare, and where we find the Rose Pogonia and
other bog-loving relatives growing, the Calopogon usually outnumbers them
all. Limodorum translated reads meadow-gift; but we find the flower
less frequently in grassy places than those who have waded into its favorite
haunts could wish.
Arethusa; Indian Pink
Arethusa bulbosa
Flowers--1 to 2 in. long, bright purple pink, solitary, violet
scented, rising from between a pair of small scales at end of smooth scape
from 5 to 10 in. high. Lip dropping beneath sepals and petals, broad,
rounded, toothed, or fringed, blotched with purple, and with three hairy
ridges down its surface. Leaf: Solitary, hidden at first, coming
after the flower, but attaining length of 6 in. Root: Bulbous.
Fruit: A 6-ribbed capsule, 1 in. long, rarely maturing.
Preferred Habitat--Northern bogs and swamps.
Flowering Season--May-June.
Distribution--From North Carolina and Indiana northward to the Fur
Countries.
One flower to a plant, and that one rarely maturing seed; a temptingly
beautiful prize which few refrain from carrying home, to have it wither on
the way; pursued by that more persistent lover than Alpheus, the
orchid-hunter who exports the bulbs to European collectors--little wonder
this exquisite orchid is rare, and that from certain of those cranberry bogs
of eastern New England, which it formerly brightened with its vivid pink, it
has now gone forever. Like Arethusa, the nymph whom Diana changed into a
fountain that she might escape from the infatuated river god, Linnaeus
fancied this flower a maiden in the midst of a spring bubbling from wet
places where presumably none may follow her.
Nodding Ladies' Tresses or Traces
Spiranthes cernua
Flowers--Small, white or yellowish, without a spur, fragrant,
nodding or spreading in 3 rows on a cylindrical, slightly twisted spike 4 or
5 in. long. Side sepals free, the upper ones arching, and united with
petals; the oblong, spreading lip crinkle-edged, and bearing minute, hairy
callosities at base. Stem: 6 in. to 2 ft. tall, with several pointed,
wrapping bracts. Leaves: From or near the base, linear, almost
grass-like.
Preferred Habitat--Low meadows, ditches, and swamps.
Flowering Season--July-October.
Distribution--Nova Scotia to the Gulf of Mexico, and westward to
the Mississippi.
This last orchid of the season, and perhaps the commonest of its
interesting tribe in the eastern United States, at least, bears flowers
that, however insignificant in size, are marvellous pieces of mechanism, to
which such men as Charles Darwin and Asa Gray have devoted hours of study
and, these two men particularly, much correspondence.
Just as a woodpecker begins at the bottom of a tree and taps his way
upward, so a bee begins at the lower and older flowers on a spike and works
up to the younger ones; a fact on which this little orchid, like many
another plant that arranges its blossoms in long racemes, depends. Let us
not note for the present what happens in the older flowers, but begin our
observations, with the help of a powerful lens, when the bee has alighted on
the spreading lip of a newly opened blossom toward the top of the spire. As
nectar is already secreted for her in its receptacle, she thrusts her tongue
through the channel provided to guide it aright, and by the slight contact
with the furrowed rostellum, it splits, and releases a boat-shaped disk
standing vertically on its stern in the passage. Within the boat is an
extremely sticky cement that hardens almost instantly on exposure to the
air. The splitting of the rostellum, curiously enough, never happens without
insect aid; but if a bristle or needle be passed over it ever so lightly, a
stream of sticky, milky fluid exudes, hardens, and the boat-shaped disk,
with pollen masses attached, may be withdrawn on the bristle just as the bee
removes them with her tongue. Each pollinium consists of two leaves of
pollen united for about half their length in the middle with elastic
threads. As the pollinia are attached parallel to the disk, they stick
parallel on the bee's tongue, yet she may fold up her proboscis under her
head, if she choose, without inconvenience from the pollen masses, or
without danger of loosening them. Now, having finished sucking the
newly-opened flowers at the top of the spike, away she flies to an older
flower at the bottom of another one. Here a marvellous thing has happened.
The passage which, when the flower first expanded, scarcely permitted a
bristle to pass, has now widened through the automatic downward movement of
the column in order to expose the stigmatic surfaces to contact with the
pollen masses brought by the bee. Without the bee's help this orchid, with a
host of other flowers, must disappear from the face of the earth. So very
many species which have lost the power to fertilize themselves now depend
absolutely on these little pollen carriers, it is safe to say that, should
the bees perish, one half our flora would be exterminated with them. On the
slight downward movement of the column in the ladies' tresses, then, as well
as on the bee's ministrations, the fertilization of the flower absolutely
depends. "If the stigma of the lowest flower has already been fully
fertilized," says Darwin, "little or no pollen will be left on its dried
surface; but on the next succeeding flower, of which the stigma is adhesive,
large sheets of pollen will be left. Then as soon as the bee arrives near
the summit of the spike she will withdraw fresh pollinia, will fly to the
lower flowers on another plant, and fertilize them; and thus, as she goes
her rounds and adds to her store of honey, she continually fertilizes fresh
flowers and perpetuates the race of autumnal spiranthes, which will yield
honey to future generations of bees."
|