Part 53

_Herbs destitute of green foliage (root-parasites), monopetalous, didynamous, the ovary one-celled with 2 or 4 parietal placentae; pod very many-seeded; seeds minute, with albumen and a very minute embryo._--Calyx persistent, 4--5-toothed or parted. Corolla tubular, more or less 2-lipped, ringent, persistent and withering; upper lip entire or 2-lobed, the lower 3-lobed. Stamens 4, didynamous, inserted on the tube of the corolla; anthers 2-celled, persistent. Ovary free, ovoid, pointed with a long style; stigma large. Capsule 1-celled, 2-valved; each valve bearing on its face one placenta or a pair. Seeds very numerous, minute.--Low, thick or fleshy herbs, bearing scales in place of leaves, lurid yellowish or brownish throughout. Flowers solitary or spiked.

[*] Flowers of two sorts, scattered along slender panicled branches.

1. Epiphegus. Upper flowers sterile, with a tubular corolla; the lower fertile, with the corolla minute and not expanding. Bracts inconspicuous.

[*][*] Flowers all alike and perfect; sterns mostly simple.

2. Conopholis. Flowers, densely spicate. Calyx deeply cleft in front. Corolla 2-lipped Stamens exserted.

3. Aphyllon. Flowers pedicellate, sometimes subsessile and thyrsoid-spicate. Calyx regularly 5-cleft. Corolla somewhat 2-lipped. Stamens included.

4. Orobanche. Flowers sessile, spicate. Calyx cleft before and behind almost to the base. Corolla 2-lipped. Stamens included.

1. EPIPHEGUS, Nutt. BEECH-DROPS. CANCER-ROOT.

Flowers racemose or spiked, scattered on the branches; the upper sterile, with a long tubular corolla and long filaments and style; the lower fertile, with a very short corolla which seldom opens, but is forced off from the base by the growth of the pod; stamens and style very short. Calyx 5-toothed. Stigma capitate, a little 2-lobed. Capsule 2-valved at the apex, with 2 approximate placentae on each valve.--Herbs slender, purplish or yellowish-brown, much branched, with small scattered scales, 6--12' high. (Name from [Greek: e)pi/], _upon_, and [Greek: phego/s], _the Beech_, because it grows on the roots of that tree.)

1. E. Virginiana, Bart. Corolla of the upper (sterile) flowers whitish and purple, 6--8'' long, curved, 4-toothed.--Common under Beech-trees, parasitic on their roots; N. Brunswick to Wisc., south to Fla. and Ark. Aug.--Oct.

2. CONOPHOLIS, Wallroth. SQUAW-ROOT. CANCER-ROOT.

Flowers in a thick scaly spike, perfect, with 2 bractlets at the base of the irregularly 4--5-toothed calyx; its tube split down on the lower side. Corolla tubular, swollen at base, strongly 2 lipped; upper lip arched, notched at the summit, the lower shorter, 3-parted, spreading. Stamens protruded. Stigma depressed. Capsule with 4 placentae, a pair on the middle of each valve.--Upper scales forming bracts to the flowers, regularly imbricate, not unlike those of a fir-cone (whence the name, from [Greek: ko~nos], _a cone_, and [Greek: pholi/s], _a scale_).

1. C. Americana, Wallroth.--Oak woods, growing in clusters among fallen leaves; N. Eng. to Mich., south to Fla. and Tenn. May, June.--A singular plant, chestnut-colored or yellowish throughout, as thick as a man's thumb, 3--6' high, covered with fleshy scales, which become dry and hard.

3. APHYLLON, Mitchell. NAKED BROOM-RAPE.

Flowers perfect, pedicellate, sometimes subsessile and thyrsoid-spicate. Calyx 5-cleft, regular. Corolla somewhat 2-lipped; the upper lip more or less spreading and 2-lobed, the lower spreading, 3-lobed. Stamens included. Stigma broadly 2-lipped or crateriform. Capsule with 4 placentae, equidistant or contiguous in pairs. Plants brownish or whitish. Flowers (purplish or yellowish) and naked scapes minutely glandular-pubescent. (Name from [Greek: a-] privative and [Greek: phy/llon], _foliage_, alluding to the naked stalks.)

[*] _Flowers solitary on long naked scapes or peduncles, without bractlets; corolla with a long curved tube and spreading 5-lobed limb._

1. A. uniflorum, Gray. (ONE-FLOWERED CANCER-ROOT.) _Stem subterranean or nearly so, very short_, scaly, often branched, each branch sending up 1--3 slender one-flowered scapes (3--5' high); _divisions of the calyx lance-awl-shaped_, half the length of the corolla, which is 1' long, with 2 yellow bearded folds in the throat, and obovate lobes.--Damp woodlands, Newf. to Va. and Tex., and west to the Pacific. April, May.

2. A. fasciculatum, Gray. _Scaly stem erect and rising 3--4' out of the ground_, mostly longer than the crowded peduncles; _divisions of the calyx triangular, very much shorter than the corolla_, which has rounded short lobes.--Sandy ground, L. Michigan to Minn., southward west of the Mississippi, and westward. On Artemisia, Eriogonum, etc. May.

[*][*] _Caulescent, flowers densely spicate, with 1--2 bractlets at base of calyx; corolla 2-lipped, the upper lip less or not at all 2-cleft._

3. A. Ludovicianum, Gray. Glandular-pubescent, branched (3--12' high); corolla somewhat curved, twice the length of the narrow lanceolate calyx-lobes; the lips equal in length. (Phelipaea Ludoviciana, _Walp._)--Minn. to Ill. and Tex., and westward.

4. OROBANCHE, Tourn. BROOM-RAPE.

Flowers spicate, sessile. Calyx cleft before and behind almost or quite to the base, the divisions usually 2-cleft. Corolla 2-lipped; upper lip erect, 2-lobed or emarginate, the lower spreading, broadly 3-lobed. Stamens included.--Old World parasites, on roots of various plants.

O. MINOR, L. A span to a foot high, pubescent, pale yellowish-brown, or with purplish-tinged flowers in a rather loose spike; corolla 6'' long.--Parasitic on clover, N. J. to Va. Sparingly and probably recently introduced.

(Addendum) O. RAMOSA, L. Often branched, 6' high or less, of a pale straw-color; flowers 3-bracteate, the lateral bracts small; calyx 4-toothed, split at the back; corolla pale blue, 6--8'' long.--On the roots of hemp and tobacco; Ky. (Int. from Eu.)

ORDER 77. LENTIBULARIACEAE. (BLADDERWORT FAMILY.)

_Small herbs (growing in water or wet places), with a 2-lipped calyx, and a 2-lipped personate corolla, 2 stamens with (confluently) one-celled anthers, and a one-celled ovary with a free central placenta, bearing several anatropous seeds, with a thick straight embryo, and no albumen._--Corolla deeply 2-lipped, the lower lip larger, 3-lobed and with a prominent palate, spurred at the base in front; the palate usually bearded. Ovary free; style very short or none; stigma 1--2-lipped. Capsule often bursting irregularly. Scapes 1--few-flowered.--The following are the two principal genera.

1. Utricularia. Calyx-lobes mostly entire. Upper lip of corolla erect. Filaments strongly incurved. Foliage dissected; bladder-bearing.

2. Pinguicula. Calyx with upper lip deeply 3- and lower 2-cleft. Corolla-lobes spreading. Filaments straighter. Terrestrial, with entire rosulate leaves next the ground.

1. UTRICULARIA, L. BLADDERWORT.

Lips of the 2-parted calyx entire, or nearly so. Corolla personate, the palate on the lower lip projecting, often closing the throat; upper lip erect. Anthers convergent.--Aquatic and immersed, with capillary dissected leaves bearing little bladders, which float the plant at the time of flowering; or rooting in the mud, and sometimes with few or no leaves or bladders. Scapes 1--few-flowered; usually flowering all summer. Bladders furnished with a valvular lid and usually with a few bristles at the orifice. (Name from _utriculus_, a little bladder.)

[*] _Upper leaves in a whorl on the otherwise naked scape, floating by means of large bladders formed of the inflated petioles; the lower leaves dissected and capillary, bearing small bladders; rootlets few or none._

1. U. inflata, Walt. Swimming free; bladder-like petioles oblong, pointed at the ends and branched near the apex, bearing fine thread-like divisions; flowers 3--10 (large, yellow); the appressed spur half the length of the corolla; style distinct.--In still water, Maine to Tex., near the coast.

[*][*] _Scapes naked (except some small scaly bracts), from immersed branching stems, which commonly swim free, bearing capillary dissected leaves with small bladders on their lobes; roots few and not affixed, or none. (Mostly perennial, propagated from year to year by tuber-like buds.)_

[+] _Cleistogamous flowers along the submersed copiously bladder-bearing stems._

2. U. clandestina, Nutt. Leaves numerous on the slender immersed stems, several times forked, capillary; scapes slender (3--5' high); lips of the yellow corolla nearly equal in length, the lower broader and 3-lobed, somewhat longer than the approximate thick and blunt spur.--Ponds, from N. Brunswick and N. Eng. to N. J., near the coast.

[+][+] _No cleistogamous flowers._

[++] _Pedicels recurved in fruit; corolla yellow._

3. U. vulgaris, L. (GREATER BLADDERWORT.) Immersed stems (1--3 deg. long) _crowded with 2--3-pinnately many-parted capillary leaves, bearing many bladders_; scapes 5--12-flowered (6--12' long); _corolla closed_ (6--9'' broad), the sides reflexed; spur conical, rather shorter than the lower lip, thick and blunt in the European and the high northern plant; in the common American plant less thick and rather acute.--Common in ponds and slow streams, Newf. to Minn., south to Va. and Tex., and westward. (Eu., Asia.)

4. U. minor, L. (SMALLER B.) _Leaves scattered_ on the thread-like immersed stems, 2--4 times _forked_, short; scapes weak, 2--8-flowered (3--7' high); _upper lip of the gaping corolla not longer than the depressed palate; spur very short and blunt, or almost none_.--Shallow water, E. Mass, to Minn., south to N. J. and Ark., and westward. (Eu.)

[++][++] _Pedicels erect in fruit, few and slender; corolla yellow._

5. U. gibba, L. _Scape_ (1--3' high) _1--2-flowered_, at base furnished with very slender short branches, bearing sparingly dissected capillary root-like leaves and scattered bladders; corolla 3--4'' broad, the lips broad and rounded, nearly equal; the _lower_ with the sides reflexed, _exceeding and approximate to the very thick and blunt conical gibbous spur_.--Shallow water, Mass. to Mich., south to Va. and Ill.; Mt. Desert (_F. M. Day_).

6. U. biflora, Lam. _Scape_ (2--5' high) _1--3-flowered_, at the base bearing somewhat elongated submersed branches with capillary root-like leaves and numerous bladders; _corolla 4--6'' broad, the spur oblong, equalling the lower lip_; seeds scale-shaped.--Ponds and shallow waters, S. Ill. and Iowa to Tex.; also S. Va. (?), and Barnstable, Mass. (_W. Deane_).

7. U. fibrosa, Walt. _Leaves_ crowded or whorled on the small immersed stems, several times forked, _capillary_; the bladders borne mainly along the stems; flowers 2--6 (6'' broad); lips nearly equal, broad and expanded, the upper undulate, concave, plaited-striate in the middle; _spur nearly linear, obtuse_, approaching and almost equalling the lower lip. (U. striata, _LeConte_.)--Shallow pools in pine barrens, L. Island and N. J. to Fla. and Ala.

8. U. intermedia, Hayne. _Leaves_ crowded on the immersed stems, _2-ranked_, 4--5 times forked, _rigid_, the divisions linear-awl-shaped, minutely bristle-toothed along the margins; _the bladders borne on separate leafless branches_; upper lip of corolla much longer than the palate; _spur conical-subulate, acute, appressed to the very broad (6--8'') lower lip and nearly as long as it_.--Shallow pools, Newf. to N. J., west to Iowa, Minn., and northward. (Eu., Asia.)

[++][++][++] _Pedicels erect in fruit, rather long; corolla violet-purple._

9. U. purpurea, Walt. Leaves whorled along the long immersed free floating stems, petioled, decompound, capillary, bearing many bladders; flowers 2--4 (6'' wide); spur appressed to the 3-lobed 2-saccate lower lip of the corolla and about half its length.--Ponds, Maine and N. Penn. to Fla., mainly near the coast; also Lake Co., Ind.

[*][*][*] _Scape solitary, slender and naked, or with a few small scales, the base rooting in the mud or soil; leaves small, awl-shaped or grass-like, often raised out of the water, commonly few or fugacious; air-bladders few on the leaves or rootlets, or commonly none._

[+] _Flower purple, solitary; leaves bearing a few delicate lobes._

10. U. resupinata, B. D. Greene. Scape (2--8' high) 2-bracted above; leaves thread-like, on delicate creeping branches; corolla (4--5'' long) deeply 2-parted; spur oblong-conical, very obtuse, shorter than the dilated lower lip and remote from it, _both ascending_, the flower resting transversely on the summit of the scape.--Sandy margins of ponds, E. Maine to R. I., near the coast; also N. New York and Presque Isle, L. Erie.

[+][+] _Flowers 2--10, (chiefly) yellow; leaves entire, rarely seen._

11. U. subulata, L. Stem capillary (3--5' high); _pedicels capillary; lower lip of the corolla flat_ or with its margins recurved, _equally 3-lobed_, much larger than the ovate upper one; _spur oblong_, acute, straight, _appressed_ to the lower lip, which it nearly equals in length.--Sandy swamps, and pine-barrens, Nantucket, Mass., to N. J., Fla., and Tex., near the coast.

Var. cleistogama, Gray. Only 1--2' high, bearing 1 or 2 evidently cleistogamous purplish flowers, not larger than a pin's head; capsule becoming 1'' long. (The unnamed Utricularia in the Man., p. 320).--With the ordinary form; Barnstable and Nantucket, Mass., pine-barrens of N. J., and southward.

12. U. cornuta, Michx. Stem strict (3'--1 deg. high), 1--5-flowered; _pedicels not longer than the calyx_; corolla 1' long, the _lower lip large and helmet-shaped_, its centre very convex and projecting, while the sides are strongly reflexed; upper lip obovate and much smaller; _spur awl-shaped, turned downward_ and outward, about as long as the lower lip.--Peat-bogs, or sandy swamps, Newf. to Minn., south to Fla. and Tex.; common.

2. PINGUICULA, Tourn. BUTTERWORT.

Upper lip of the calyx 3-cleft, the lower 2-cleft. Corolla with an open hairy or spotted palate, the lobes spreading.--Small and stemless perennials, growing on damp rocks, with 1-flowered scapes, and broad and entire leaves, all clustered at the root, soft-fleshy, mostly greasy to the touch (whence the name, from _pinguis_, fat).

1. P. Vulgaris, L. Leaves ovate or elliptical; scape and calyx a little pubescent; lips of the violet corolla very unequal, the tube funnel-form; spur straightish.--Wet rocks, northern N. Eng. and N. Y. to Minn., and far northward. (Eu., Asia.)

ORDER 78. BIGNONIACEAE. (BIGNONIA FAMILY.)

_Woody plants, monopetalous, didynamous or diandrous, with the ovary commonly 2-celled by the meeting of the two parietal placentae or of a projection from them, many-ovuled; fruit a dry capsule, the large flat winged seeds with a flat embryo and no albumen, the broad and leaf-like cotyledons notched at both ends._--Calyx 2-lipped, 5-cleft, or entire. Corolla tubular or bell-shaped, 5-lobed, somewhat irregular or 2-lipped, deciduous; the lower lobe largest. Stamens inserted on the corolla; the fifth or posterior one, and sometimes the shorter pair also, sterile or rudimentary; anthers of 2 diverging cells. Ovary free, bearing a long style, with a 2-lipped stigma.--Leaves compound or simple, opposite, rarely alternate. Flowers large and showy.--Chiefly a tropical family.

1. Bignonia. Pod flattened parallel with the partition. Leaves compound, tendril-bearing.

2. Tecoma. Pod flattish contrary to the partition. Leaves compound, without tendrils.

3. Catalpa. Pod terete. Fertile stamens only 2. Trees; leaves simple.

1. BIGNONIA, Tourn.

Calyx truncate, or slightly 5-toothed. Corolla somewhat bell-shaped, 5-lobed and rather 2-lipped. Stamens 4, often showing a rudiment of the fifth. Capsule linear, 2-celled, flattened parallel with the valves and partition. Seeds transversely winged.--Woody climbers, with chiefly compound leaves, terminating in a tendril. (Named for the _Abbe Bignon_.)

1. B. capreolata, L. (CROSS-VINE.) Smooth; leaves of 2 ovate or oblong leaflets and a branched tendril, often with a pair of accessory leaves in the axil resembling stipules; peduncles few and clustered, 1-flowered; corolla orange, 2' long; pod 6' long; seeds with the wing 11/2' long.--Rich soil, Va. to S. Ill and south to Fla. and La. April. Climbing tall trees; a transverse section of the wood showing a cross.

2. TECOMA, Juss. TRUMPET-FLOWER.

Calyx bell-shaped, 5-toothed. Corolla funnel-form, 5-lobed, a little irregular. Stamens 4. Capsule 2-celled, with the partition at right angles to the convex valves. Seeds transversely winged.--Woody, with compound leaves, climbing by aerial rootlets. (Abridged from the Mexican name.)

1. T. radicans, Juss. (TRUMPET CREEPER.) Leaves pinnate; leaflets 9--11, ovate, pointed, toothed; flowers corymbed; stamens not protruded beyond the tubular-funnel-form orange and scarlet corolla (21/2--3' long); pod oblanceolate, 4--5' long.--Moist soil, Penn. to Ill., south to Fla. and Tex. Common in cultivation farther north.

3. CATALPA, Scop., Walt. CATALPA. INDIAN BEAN.

Calyx deeply 2-lipped. Corolla bell-shaped, swelling; the undulate 5-lobed spreading border irregular and 2-lipped. Fertile stamens 2, or sometimes 4; the 1 or 3 others sterile and rudimentary. Capsule very long and slender, nearly cylindrical, 2-celled, the partition at right angles to the valves. Seeds winged on each side, the wings cut into a fringe.--Trees, with ovate or cordate and mainly opposite leaves. (The aboriginal name.)

1. C. speciosa, Warder. A large and tall tree, with thick bark; leaves ample, heart-shaped, long-acuminate; corolla 2' long, nearly white, inconspicuously spotted, with obconical tube and slightly oblique limb, the lower lobe emarginate; capsule thick.--Low rich woodlands, S. Ind. to Tenn., Mo., and Ark. May.

C. BIGNONIOIDES, Walt., of Ga., Ala. and Miss., very widely cultivated, and formerly including the above species, is a low much branched tree, with thin bark, smaller (11/2' long) thickly spotted corolla (with oblique limb and lower lobe entire), and a much thinner capsule.

ORDER 79. PEDALIACEAE.

_Herbs, with chiefly opposite simple leaves, and flowers as of the preceding Order, except in structure of ovary and fruit, the former being 1-celled, the latter fleshy-drupaceous, with wingless seeds and thick entire cotyledons._--Ovary (in ours) 1-celled, with 2 parietal intruded placentae expanded into 2 broad lamellae or united into a central columella.

1. MARTYNIA, L. UNICORN-PLANT.

Calyx 5-cleft, mostly unequal. Corolla gibbous, bell-shaped, 5-lobed and somewhat 2-lipped. Fertile stamens 4, or only 2. Fruit fleshy, the flesh at length falling away in 2 valves; the inner part woody, terminated by a beak, which at length splits into 2 hooked horns, and opens at the apex between the horns, imperfectly 5-celled, owing to the divergence of the two plates of each placenta, leaving a space in the centre, while by reaching and cohering with the walls of the fruit they form 4 other cells. Seeds several, wingless, with a thick roughened coat.--Low branching annuals, clammy-pubescent, exhaling a heavy odor, stems thickish; leaves simple, rounded; flowers racemed, large. (Dedicated to _Prof. John Martyn_, of Cambridge, England.)

1 M. proboscidea, Glox. Leaves heart-shaped, oblique, entire or undulate, the upper alternate; corolla dull white or purplish, or spotted with yellow and purple; endocarp of the fruit crested on one side, long-beaked.--Banks of the Mississippi and its lower tributaries, from S. Ind., Ill., and Iowa, to northern Mexico. Also cultivated and naturalized farther north.

ORDER 80. ACANTHACEAE. (ACANTHUS FAMILY.)

_Chiefly herbs, with opposite simple leaves, didynamous or diandrous stamens, inserted on the tube of the more or less 2-lipped corolla, the lobes of which are convolute or imbricated in the bud; fruit a 2-celled and few- (4--12-) seeded capsule; seeds anatropous, without albumen, usually flat and supported by hooked projections of the placentae (retinacula)._--Flowers commonly much bracted. Calyx 5-cleft. Style thread-form; stigma simple or 2-cleft. Pod loculicidal, usually flattened contrary to the valves and partition. Cotyledons broad and flat.--Mucilaginous and slightly bitter, not noxious. A large family in the warmer parts of the world; represented in gardens by THUNBERGIA, which differs from the rest by the globular pod and seeds, the latter not on hooks.

[*] Corolla not obviously bilabiate, the 5 lobes broad and roundish, spreading; stamens 4.

1. Calophanes. Calyx-lobes long-filiform. Capsule 2--4-seeded.

2. Ruellia. Calyx-lobes mostly linear or lanceolate. Capsule 6--20-seeded.

[*][*] Corolla bilabiate, upper lip erect and concave, lower spreading; stamens 2.

3. Dianthera. Capsule obovate, flattened, 4-seeded.

1. CALOPHANES, Don.

Calyx deeply 5-cleft or parted; its lobes elongated setaceous-acuminate or aristiform. Corolla funnel-form, with ample limb, convolute in the bud. Stamens 4, the anthers mucronate or sometimes aristate at base. Ovules a single pair in each cell. Capsule oblong-linear, 2--4-seeded.--Low branching perennials, pubescent or hirsute, with proportionally large axillary nearly sessile flowers (solitary or few), and blue corolla. (Name from [Greek: kalo/s], _beautiful_, and [Greek: phai/no], _to appear_.)

1. C. oblongifolia, Don. Stems visually erect and simple, 1/2--1 deg. high; leaves from narrowly oblong to oval, very obtuse, sessile (1' long or less); corolla blue, sometimes purple-dotted or mottled, seldom 1' long; calyx-lobes nearly distinct, filiform-setaceous, hirsute.--Pine-barrens, S. Va. to Fla.

2. RUELLIA, Plumier.

Calyx 5-parted. Corolla funnel-form, with spreading ample border, convolute in the bud. Stamens 4, the cells of the somewhat arrow-shaped anthers parallel and nearly equal. Capsule narrow, in our species somewhat flattened, contracted and seedless at the base, above 8--12-seeded. Seeds with a mucilaginous coat, when wet exhibiting under the microscope innumerable tapering short bristles, their walls marked with rings or spirals.--Perennials, with rather large and showy blue or purple flowers, mostly in axillary clusters, sometimes also with small flowers precociously close-fertilized in the bud. Calyx often 2-bracteolate. (Named for the early herbalist, _John Ruelle_.)

1. R. ciliosa, Pursh. _Hirsute_ with soft whitish hairs (1--3 deg. high); _leaves nearly sessile, oval_ or ovate-oblong (1--2' long); flowers 1--3 and almost sessile in the axils; _tube of the corolla_ (1--11/2' long) fully _twice the length of the setaceous calyx-lobes_; the throat short.--Dry ground, Mich. to Minn., south to Fla. and La. June--Sept.--Var. AMBIGUA, Gray. Sparingly hirsute-pubescent or glabrate; leaves ovate-oblong, usually short-petioled, larger; tube of corolla little exceeding the hardly hirsute calyx.--Va. and Ky. to Ala. Appearing like a hybrid with the next.

2. R. strepens, L. _Glabrous or sparingly pubescent_ (1--4 deg. high); _leaves narrowed at base into a petiole_, ovate, obovate, or mostly oblong (21/2--5' long); _tube of the corolla_ (about 1' long) little longer than the dilated portion, _slightly exceeding the lanceolate or linear calyx-lobes_.--Rich soil, Penn. to Wisc., south to Fla. and Tex. July--Sept.--Var. CLEISTANTHA, Gray. Leaves commonly narrower and oblong; flowers for most of the season cleistogamous.--Common with the ordinary form.

3. DIANTHERA, Gronov. WATER-WILLOW.

Calyx 5-parted. Corolla deeply 2-lipped; the upper lip erect, notched; the lower spreading, 3-parted, external in the bud. Stamens 2; anthers 2-celled, the cells separated and somewhat unequal. Capsule obovate, flattened, contracted at base into a short stalk, 4-seeded.--Perennial herbs, growing in water or wet places, with entire leaves, and purplish flowers in axillary peduncled spikes or heads. (Name formed of [Greek: di/s], _double_, and [Greek: a)nthera/], _anther_; the separated cells giving the appearance of two anthers on each filament.)