Part 160 (2/2)

Ovary 3-celled, with the thick placentae in the axis. Filaments 3, very short. Style slender; stigma capitate-3-lobed. Capsule often 3-winged.

(Named for _J. Burmann_, an early Dutch botanist.)

1. B. biflra, L. Stem low and slender (2--4' high), 2-flowered at the summit, or soon several-flowered; perianth (2--3” long) bright blue, 3-winged.--Peaty bogs, Va. to Fla.

ORDER 110. ORCHIDaCEae. (ORCHIS FAMILY.)

_Herbs, clearly distinguished by their perfect irregular flowers, with 6-merous perianth adnate to the 1-celled ovary, with innumerable ovules on 3 parietal placentae, and with either one or two gynandrous stamens, the pollen cohering in ma.s.ses._ Fruit a 1-celled 3-valved capsule, with innumerable minute seeds, appearing like fine saw-dust. Perianth of 6 divisions in 2 sets; the 3 outer (_sepals_) mostly of the same petal-like texture and appearance as the 3 inner (_petals_). One of the inner set differs more or less in figure, direction, etc., from the rest, and is called the _lip_; only the other two taking the name of _petals_ in the following descriptions. The lip is really the upper petal, i.e. the one next to the axis, but by a twist of the ovary of half a turn it is more commonly directed forward and brought next the bract. Before the lip, in the axis of the flower, is the _column_, composed of a single stamen, or in Cypripedium of two stamens and a rudiment of a third, variously coherent with or borne on the style or thick fleshy stigma; anther 2-celled; each cell containing one or more ma.s.ses of pollen (_pollinia_) or the pollen granular (in Cypripedium).

Stigma a broad glutinous surface, except in Cypripedium.--Perennials, often tuber-bearing or tuberous-rooted; some epiphytes. Leaves parallel-nerved, all alternate. Flowers often showy, commonly singular in shape, solitary, racemed, or spiked, each subtended by a bract,--in all arranged for fertilization by the aid of insects, very few capable of unaided self-fertilization.

Tribe I. EPIDENDREae. Anther terminal, erect or inclined, operculate.

Pollinia smooth and waxy, 4 or 8 (2 or 4 in each cell), distinct, or those in each cell (or all in n. 3 and 7) united at base. (Pollinia 8 only in n. 7 of our genera.)

[*] Green-foliaged plants, from solid bulbs, with 1 or 2 leaves.

[+] Column very short; leaf solitary.

1. Microstylis. Flowers racemose, minute, greenish. Petals filiform.

[+][+] Column elongated; leaves radical.

[++] Whole plant (except the flowers) green.

2. Liparis. Leaves 2. Raceme few-flowered. Lip flat, entire.

3. Calypso. Leaf solitary. Flower large, solitary. Lip saccate.

[++][++] A single green autumnal leaf; otherwise mainly brownish or purplish.

4. Tipularia. Raceme many-flowered; flowers small, greenish; lip 3-lobed.

5. Aplectrum. Raceme loose; flowers rather large; lip 3-ridged, not spurred or saccate.

[*][*] Leafless, with coralloid roots; whole plant brownish or yellowish; flowers racemose.

6. Corallorhiza. Pollinia 4, in 2 pairs. Flower gibbous or somewhat spurred, and lip with 1--3 ridges; sepals and petals 1--3-nerved.

7. Hexalectris. Pollinia 8, united. Flower not gibbous; sepals and petals several-nerved; lip with 5--6 ridges.

Tribe II. NEOTTIEae. Anthers erect upon the back of the column at the summit, or terminal and opercular. Pollinia granular or powdery, more or less cohering in 2 or 4 delicate ma.s.ses, and attached at the apex to the beak of the stigma.

[*] Anthers without operculum, erect upon the back of the short column.

Flowers small, in spikes or racemes.

8. Listera. Stem from a fibrous root, 2-foliate. Lip flat, 2-lobed.

9. Spiranthes. Stems leafy below, from tuberous-fascicled roots. Flowers 1--3-ranked in a twisted spike. Lip embracing the column below, with 2 callosities at base.

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