Part 76

12. P. Illinoensis, Morong. _Stem stout, branching_ towards the summit; floating leaves opposite, oval or ovate (2--5' long by 11/2--2' broad), 19--25-nerved, rounded or subcordate at base, with a short blunt point at apex, on short petioles, _submersed leaves rather few, oblong-elliptical_, acute at each end, _usually ample_ (largest 8' by 11/2'); _stipules coarse, obtuse, strongly bicarinate_ (2' long); peduncles often clustered at the summit (2--4' long), thickening upward; _fruit roundish-obovate_ (13/4--2'' long), 3-keeled on the back, middle keel prominent; nutlet flattened and slightly impressed on the sides, obtuse or pointed at base; apex of embryo directed transversely inward.--Streams and ditches, western N. Y. to Ill., Iowa, and Minn. Very near the last.

13. P. heterophyllus, Schreb. _Stem slender, very branching_ below; floating leaves mostly thin, variable, but with a short blunt point, 9--15-nerved, usually 1--2' long and 6--9'' wide; submersed ones usually lanceolate or linear-lanceolate, acuminate or cuspidate, narrowed toward the base, about 7-nerved on the stem and 3-nerved on the branches; upper ones petioled, lower sessile; _stipules obtuse_, loose; peduncles somewhat thickened upward; fruit small, roundish, compressed, scarcely keeled; embryo annular above. (P. gramineus, _Fries_.)--Still or flowing water, common. Varies exceedingly in its submersed leaves, peduncles, etc.; the var. GRAMINIFOLIUS (Fries), growing in rapid streams, with stems much elongated and less branched, and the flaccid submersed leaves 2--7' long by 2--10'' wide.

Var. (?) myriophyllus, Robbins. Sending up from running rootstocks many short repeatedly dichotomous and densely leafy stems; fertile stems very slender; floating leaves small, delicate, lance-oblong, on long filiform petioles; submersed stem-leaves larger, early perishing; those of the branches (deep-green) linear-oblanceolate, very small (3/4--1' long), acute, sometimes minutely serrulate; spike slender, loosely-flowered, much shorter than the thickened peduncle.--Apponaug Pond, R. I., without fruit.

13^a. P. Zizii, Mert. & Koch. Resembling P. lucens, but smaller, much branched at base; _upper leaves coriaceous or subcoriaceous, long-petioled_ and _sometimes emersed_, the others subsessile, all usually numerous, undulate and _shining_; peduncle elongated. (P. lucens, var. minor, _Nolte_. Also P. gramineus, var. (?) spathulaeformis, _Robbins_; P. spathaeformis, _Tuckerm._; "P. varians, _Morong_.")--N. Eng to Fla., and westward. Connecting with the next section. (Eu.)

Sec. 2. _Leaves all submersed and similar, mostly sessile, membranaceous and dilated, lanceolate, oblong, or oval; stipules obtuse, becoming loose._

14. P. lucens, L. Stem thick, branching, sometimes very large; _leaves more or less petioled_, oval or lanceolate, _mucronate_, often rough serrulate, _frequently shining_; peduncles often elongated; _fruit_ roundish and compressed, _with obtuse margins, slightly keeled_; embryo circularly incurved above.--Ponds, N. Eng. to Fla., west to the Pacific. Aug., Sept. (Eu.)

Var. (?) Connecticutensis, Robbins. Stem flexuous; _leaves_ all submersed, nearly sessile, lanceolate, _acuminate, crisped, not shining nor serrulate; fruit larger, distinctly keeled_; nutlet thick and hard.--Lake Saltonstall, East Haven, Conn.

15. P. praelongus, Wulf. Stem very long, branching, flexuous; _leaves_ lance-oblong or lanceolate (sometimes 7' long), _half-clasping, obtuse with a boat-shaped cavity_ at the extremity, thence splitting on pressure; stipules scarious, very obtuse; spikes rather loose-flowered; _peduncles very long_ (sometimes reaching 20'); _fruit_ obliquely obovate, compressed, _sharply keeled_ when dry; style terminating the nearly straight face; curve of the embryo oval and longitudinal.--Ponds and large rivers, N. Scotia to Mass., west to Minn. and Iowa. Sept., Oct.--Stem white; foliage bright green. (Eu.)

16. P. perfoliatus, L. Stem branching; _leaves orbicular, ovate or lanceolate from a cordate-clasping base_, usually obtuse and often minutely serrulate; peduncles short, cylindrical; _fruit_ irregularly obovate, _obtusely margined_; embryo incurved in an oval.--Ponds and slow streams, common. N. Scotia to Fla., west to Minn. and Iowa. Sept., Oct. (Eu.)

Var. lanceolatus, Robbins. Larger; _leaves long-lanceolate_ from a cordate clasping base and _acuminate_, wavy, 3--41/2' long; _peduncles thickened upward_.--Same range as the species, and extending west to the Pacific.

17. P. crispus, L. _Stem compressed; leaves linear-oblong_, half-clasping, obtuse, _serrulate, crisped-wavy, 3-nerved; fruit long-beaked_; upper portion of the embryo incurved in a large circle.--Flowing and stagnant waters, Mass. to N. J. and Va., west to western N. Y. June, July. (Eu.)

18. P. Mysticus, Morong. _Stem very slender_ and irregularly branching, nearly filiform (1--3 deg. high); _leaves oblong-linear_ (1/2--11/2' long by 2--3'' wide), 5--7-nerved, _finely undulate and entire, obtuse or bluntly pointed, abruptly narrowing at base, sessile or partly clasping_; spikes few, capitate (4--6-flowered). on erect peduncles (1--2' long); fruit (immature) obovate, small (hardly 3/4'' long), _obscurely 3-keeled on the back_, a little beaked by the slender recurved style.--Mystic Pond, Medford, Mass.

Sec. 3. _Leaves all submersed and similar, mostly membranaceous and sessile, linear or setaceous._

[*] _Stipules free from the sheathing base of the leaf._

19. P. zosteraefolius, Schum. _Stem branching, wing-fattened; leaves_ linear and grass-like (commonly 4' by 11/2''), _abruptly pointed, with many fine and 3 larger nerves_; stipules (seen young) oblong, very obtuse; _spikes cylindrical_, 12--15-flowered, _not half as long as the peduncle_; fruit obliquely obovate, somewhat keeled and with slight teeth on the back, the sides not impressed, the face arching and terminated by the short style; _summit of the large embryo lying transverse to the fruit_. (P. compressus, _Fries_; not _L._?)--Still and slow-flowing waters, N. Eng. to N. J., Iowa, and Minn. Aug., Sept. (Eu.)

20. P. Hillii, Morong. Stem slender, _widely branching, flattish_; leaves linear, _acute_ (1--21/2' long by 1/2--11/4'' wide), _3-nerved_, the lateral nerves delicate and near the margin; stipules whitish, striate, obtuse (3--5'' long); _spikes capitate_ (3--6-fruited), _on short spreading or recurved peduncles_; fruit as in the last.--Mich. and western N. Y.

21. P. obtusifolius, Mertens & Koch. _Stem flattened, very branching; leaves_ linear, tapering toward the base, obtuse and mucronate or very acute, _3- (rarely 5-) nerved; stipules elongated_, very obtuse; _spike ovate, continuous_, 5--8-flowered, _about the length of the peduncle_; fruit oval, apiculate with the style, not keeled when fresh, _upper portion of embryo_ coiled inward and _lying transverse to the fruit_.--Slow streams and ponds, Canada and N. Eng. to western N. Y. and Mich. Sept., Oct. (Eu.)

22. P. pauciflorus, Pursh. _Stem filiform, flattish and very branching; leaves narrowly linear_ (1--2' long and seldom 1/2'' wide), acute, _obscurely 3-nerved; stipules obtuse; spikes_ capitate, 1--4- _(usually 2-) flowered_, on short club-shaped peduncles; _fruit roundish-lenticular_; the _back_ more or less _crested_; upper portion of the embryo incurved in a circle.--Still or stagnant waters, N. Brunswick to Ga., Iowa, Minn., and westward.

Var. Niagarensis, Gray. Stem often longer (1--3 deg.); leaves larger (11/2--31/2' long by 1'' wide or less), 3--5-nerved at base, very acute and mucronate, narrowed to the subpetiolate base. (P. Niagarensis, _Tuckerm_.)--Running water, Great Lakes to S. C.; also in Cal.

23. P. pusillus, L. _Stem slender_, flattish or nearly cylindrical, often very branching; _leaves narrow- or setaceous-linear_, acuminate, _acute or subacute, 1--3-nerved_, furnished with _translucent glands_ on each side at the base; stipules at first obtuse; spikes interrupted or capitate, 2--8-flowered, on rather long peduncles; _fruit_ obliquely elliptical, _scarcely keeled; apex of embryo_ incurved and _directed obliquely downward_.--Pools and ditches, N. Scotia to N. J., west to Minn. and Mo., and westward.--Leaves sometimes almost setaceous (var. tenuissimus, _Koch_).

Var. polyphyllus, Morong. Dwarf form (3--5' high), divaricately branching from the base, very leafy throughout; leaves very obtuse, not cuspidate, 3-nerved; non-flowering but abundantly provided with propagating buds which are formed on the thickened and hardened ends of the branches and closely invested by imbricated leaves.--In a shallow pool, S. Natick, Mass.

24. P. mucronatus, Schrad. Resembling P. pusillus, but stem less branching; _leaves broader_ (almost 1'' wide), _often 5-nerved; spikes interrupted_. (P. pusillus, var. major, _Fries_.)--N. Brunswick to western N. Y., Mich., and Minn. July. (Eu.)

25. P. gemmiparus, Robbins. Stem filiform, branching, terete, varying greatly in height; _leaves hair-like_, sometimes not as broad as the stem, often with no apparent midrib, _tapering to the finest point_ (1--3' long), bi-glandular at base; stipules 1/2--1' long; spikes few (3--6-flowered), _interrupted_, on long filiform peduncles; _propagating buds very numerous_; fruit like that of P. pusillus, very rare. (P. pusillus, var.? gemmiparus, _Robbins_.)--Slow-moving streams and still water, Mass. Aug., Sept.

26. P. Tuckermani, Robbins. _Very slender and delicate_ from a creeping rootstock, of a fine light green; stem filiform with several short and repeatedly dichotomous leaf-bearing branches; _leaves_ thin and flat, but _setaceous and tapering to near the fineness of a hair_ (1--4' long and {1/3}'' extreme width), obscurely 1--3-nerved, with a few coarse reticulations; stipules rather persistent below, {1/3}' long, obtuse; _peduncle solitary, very long_, rather thickened upward; _spike 4--8-flowered, in fruit continuous, oblong; fruit thick-lenticular_, obscurely 3-keeled; _nutlet slightly impressed on the sides; shell thick and hard_; embryo nearly annular.--Cold ponds, White Mountains of N. H., N. Y., and N. J.

[*][*] _Stipules united with the sheathing base of the leaf._

27. P. pectinatus, L. _Stem filiform_, repeatedly dichotomous; _leaves very narrowly linear_, attenuate to the apex, 1-nerved with a few transverse veins; _spikes interrupted_, on long filiform peduncles; fruit obliquely broad-obovate, compressed, _bluntly keeled_; shell of nutlet very thick; _embryo spirally incurved_.--N. Brunswick to Fla., westward across the continent. Aug.--Oct. (Eu.)

28. P. marinus, L. Resembling narrow-leaved forms of the last species, _low and very leafy_; peduncles much elongated; _fruit much smaller_ (1'' long) and thinner, round-obovate, _not keeled_ upon the rounded back, tipped with the broad sessile stigma; _embryo annular_.--Western N. Y., Ill., Mich., and southward. Probably the range of this species is much more extensive than indicated, as it has been confounded with P. pectinatus.

29. P. Robbinsii, Oakes. _Stem_ ascending from a creeping base, _rigid_, very branching, _invested by the bases of the leaves and stipules; leaves crowded in two ranks, recurved-spreading_, narrow-lanceolate or linear (3--5' long and 2--3'' wide), acuminate, _ciliate-serrulate_ with translucent teeth, many-nerved; stipules obtuse when young, their nerves soon becoming bristles; _spikes numerous, loosely few-flowered_, on short peduncles; fruit oblong-obovate (2'' long), _keeled with a broadish wing_, acutely beaked; embryo stout, ovally annular.--In ponds and slow streams, N. Brunswick to N. J., the N. shore of L. Superior, and far westward.

4. RUPPIA, L. DITCH-GRASS.

Flowers perfect, 2 or more approximated on a slender spadix, which is at first enclosed in the sheathing spathe-like base of a leaf, entirely destitute of floral envelopes, consisting of 2 sessile stamens, each with 2 large and separate anther-cells, and 4 small sessile ovaries, with solitary campylotropous suspended ovules; stigma sessile, depressed. Fruit small obliquely ovate pointed drupes, each raised on a slender stalk which appears after flowering; the spadix itself also then raised on an elongated thread-form peduncle. Embryo ovoid, with a short and pointed plumule from the upper end, by the side of the short cotyledon.--Marine herbs, growing under water, with long and thread-like forking stems, and slender almost capillary alternate leaves, sheathing at the base. Flowers rising to the surface at the time of expansion. (Dedicated to _H. B. Ruppius_, a German botanical author of the early part of the 18th century.)

1. R. maritima, L. Leaves linear-capillary; nut ovate, obliquely erect, 11/2'' long; fruiting peduncles capillary (3--6' long); stipes 1--12'' long.--Shallow bays, along the entire coast; also occasionally in saline places in the interior. (Eu., Asia, etc.)

5. ZANNICHELLIA, Micheli. HORNED PONDWEED.

Flowers monoecious, sessile, naked, usually both kinds from the same axil; the sterile consisting of a single stamen, with a slender filament bearing a 2--4-celled anther; the fertile of 2--5 (usually 4) sessile pistils in the same cup-shaped involucre, forming obliquely oblong nutlets in fruit, beaked with a short style, which is tipped by an obliquely disk-shaped or somewhat 2-lobed stigma. Seed orthotropous, suspended, straight. Cotyledon taper, bent and coiled.--Slender branching herbs, growing under water, with mostly opposite long and linear thread-form entire leaves, and sheathing membranous stipules. (Named in honor of _Zannichelli_, a Venetian botanist.)

1. Z. palustris, L. Style at least half as long as the fruit, which is flattish, somewhat incurved, even, or occasionally more or less toothed on the back (not wing-margined in our plant), nearly sessile; or, in var. PEDUNCULATA, both the cluster and the separate fruits evidently peduncled.--Ponds and slow streams, throughout N. America, but not common. July. (Eu., Asia.)

6. ZOSTERA, L. GRASS-WRACK. EEL-GRASS.

Flowers monoecious; the two kinds naked and sessile and alternately arranged in two rows on the midrib of one side of a linear leaf-like spadix, which is hidden in a long and sheath-like base of a leaf (spathe); the sterile flowers consisting of single ovate or oval 1-celled sessile anthers, as large as the ovaries, and containing a tuft of threads in place of ordinary pollen; the fertile of single ovate-oblong ovaries attached near their apex, tapering upward into an awl-shaped style, and containing a pendulous orthotropous ovule; stigmas 2, long and bristle-form, deciduous. Utricle bursting irregularly, enclosing an oblong longitudinally ribbed seed (or nutlet). Embryo short and thick (proper cotyledon almost obsolete), with an open chink or cleft its whole length, from which protrudes a doubly curved slender plumule.--Grass-like marine herbs, growing wholly under water, from a jointed creeping stem or rootstock, sheathed by the bases of the very long and linear, obtuse, entire, grass-like, ribbon-shaped leaves (whence the name, from [Greek: zoste/r], _a band_).

1. Z. marina, L. Leaves obscurely 3--5-nerved.--Common in shoal water of bays along the coast, from Newf. to Fla. (Eu.)

7. NAIAS, L. NAIAD.

Flowers dioecious or monoecious, axillary, solitary and sessile; the sterile consisting of a single stamen enclosed in a little membranous spathe; anther at first nearly sessile, the filament at length elongated. Fertile flowers consisting of a single ovary tapering into a short style; stigmas 2--4, awl-shaped; ovule erect, anatropous. Fruit a little seed-like nutlet, enclosed in a loose and separable membranous epicarp. Embryo straight, the radicular end downward.--Slender branching herbs, growing under water, with opposite and linear leaves, somewhat crowded into whorls, spinulose-toothed, sessile and dilated at base. Flowers very small, solitary, but often clustered with the branch-leaves in the axils; in summer. ([Greek: Naia/s], _a water-nymph_.)

1. N. marina, L. _Stem rather stout and often armed with broad prickles; leaves broadly linear_ (3--18'' long), _coarsely and sharply toothed_, the dilated base entire; fruit 2--21/2'' long; _seed very finely lineate, oblong_, slightly compressed. (N. major, _All._)--Marshes and salt-springs of western N. Y. and Mich. Teeth of one or more brownish cells upon a many-celled base. (Eu.)

Var. gracilis, Morong. Internodes long (1--3') and nearly naked, with only a few teeth above; leaves very narrow, the dilated base also toothed; fruit smaller.--Canoga marshes, western N. Y.; also in Fla.

Var. recurvata, Dudley. Stems short, inclined to be dichotomously branched, recurved-spreading; leaves usually recurved, the teeth prominent, the dilated base with a projecting tooth each side.--Cayuga marshes, N. Y.

2. N. flexilis, Rostk. & Schmidt. _Stems usually very slender; leaves very narrowly linear_ (1/2--1' long), _very minutely serrulate_; fruit 11/2'' long, narrowly oblong; _seeds lance-oval, smooth and shining_.--Ponds and slow streams, N. Scotia to S. C., Iowa and Minn. Teeth on the margins of the leaves 1-celled. (Eu.)--Var. ROBUSTA, Morong. Stem stout, few-leaved, sparsely branching, elongated; leaves flat, abruptly acute.--E. Mass., Mich., and Tex.

3. N. Indica, Cham., var. gracillima, A. Br. Branches alternate; _leaves_ very narrowly linear, _nearly capillary_, straight, _serrate, the rounded lobes of the sheathing base spinulose-ciliate; fruit linear, impressed-dotted between the numerous ribs_.--Mass. to Penn., west to Ind. and Mo. Teeth of 3 cells each.

ORDER 127. ERIOCAULEAE. (PIPEWORT FAMILY.)

_Aquatic or marsh herbs, stemless or short-stemmed, with a tuft of fibrous roots, a cluster of linear and often loosely cellular grass-like leaves, and naked scapes sheathed at the base, bearing dense heads of monoecious or rarely dioecious small 2--3-merous flowers, each in the axil of a scarious bract; the perianth double or rarely simple, chaffy; anthers introrse_; the fruit a _2--3-celled 2--3-seeded capsule_; seeds pendulous, orthotropous; embryo at the apex of mealy albumen.--Chiefly tropical plants, a few in northern temperate regions.

1. Eriocaulon. Perianth double, the inner (corolla) tubular-funnel-form in the staminate flowers; stamens twice as many as its lobes (4). Anthers 2-celled.

2. Paepalanthus. Perianth as in the last; stamens only as many as the corolla-lobes (3). Anthers 2-celled.

3. Lachnocaulon. Perianth simple, of 3 sepals. Stamens 3, monadelphous below. Anthers 1-celled.

1. ERIOCAULON, L. PIPEWORT.

Flowers monoecious and androgynous, i.e. both kinds in the same head, either intermixed, or the central ones sterile and the exterior fertile, rarely dioecious. _Ster. Fl._ Calyx of 2 or 3 keeled or boat-shaped sepals, usually spatulate or dilated upward. Corolla tubular, 2--3-lobed, each of the lobes bearing a black gland or spot. Stamens twice as many, one inserted at the base of each lobe and one in each sinus; anthers 2-celled. Pistils rudimentary. _Fert. Fl._ Calyx as in the sterile flowers, often remote from the rest of the flower (therefore perhaps to be viewed as a pair of bractlets). Corolla of 2 or 3 separate narrow petals. Stamens none. Ovary often stalked, 2--3-lobed, 2--3-celled; style 1; stigmas 2 or 3, slender. Capsule membranaceous, loculicidal.--Leaves mostly smooth, loosely cellular and pellucid, flat or concave above. Scapes or peduncles terminated by a single head, involucrate by some outer empty bracts. Flowers, also the tips of the bracts, etc., usually white-bearded or woolly. (Name compounded of [Greek: e)/rion], _wool_, and [Greek: kaulo/s], _a stalk_, from the wool at the base of the scape.)--Our species are all stemless, wholly glabrous excepting at the base and the flowers, with a depressed head and dimerous flowers.

1. E. decangulare, L. _Leaves obtuse_, varying from linear-lanceolate to linear-awl-shaped, rather rigid; scapes 10--12-ribbed (1--3 deg. high); head hemispherical, becoming globular (2--7'' wide); scales of the involucre acutish, straw-color or light brown; _chaff_ (bracts among the flowers) _pointed_.--Pine-barren swamps, N. J. to Fla. July--Sept.

2. E. gnaphalodes, Michx. _Leaves spreading_ (2--5' long), _grassy-awl-shaped_, rigid, or when submersed thin and pellucid, tapering gradually to a _sharp point_, mostly shorter than the sheath of the _10-ribbed scape_; scales of the involucre very obtuse, turning lead-color; _chaff obtuse_.--Pine-barren swamps, N. J. to Fla.

3. E. septangulare, Withering. _Leaves short_ (1--3' long), _awl-shaped, pellucid_, soft and very cellular; _scape 4--7-striate_, slender, 2--6' high, or when submersed becoming 1--6 deg. long, according to the depth of the water; _chaff acutish_; head 2--3'' broad; the bracts, chaff, etc., lead-color, except the white coarse beard.--In ponds or along their borders, Newf. to N. J., west to Ind., Mich., and Minn. July, Aug. (Eu.)

2. PAEPALANTHUS, Martius.

Stamens as many as the (often involute) lobes of the funnel-form corolla of the sterile flowers, and opposite them, commonly 3, and the flower ternary throughout. Otherwise nearly as in Eriocaulon. (Name from [Greek: paipa/le], _dust_ or _flour_, and [Greek: a)/nthos], _flower_, from the meal-like down or scurf of the heads and flowers of many South American species.)

1. P. flavidulus, Kunth. Tufted, stemless; leaves bristle-awl-shaped (1' long); scapes very slender, simple, minutely pubescent (6--12' high), 5-angled; bracts of the involucre oblong, pale straw-color, those among the flowers mostly obsolete; perianth glabrous; sepals and petals of the fertile flowers linear-lanceolate, scarious-white.--Low pine-barrens, S. Va. to Fla.

3. LACHNOCAULON, Kunth. HAIRY PIPEWORT.

Flowers monoecious, etc., as in Eriocaulon. Calyx of 3 sepals. Corolla none! _Ster. Fl._ Stamens 3; filaments below coalescent into a club-shaped tube around the rudiment of a pistil, above separate and elongated; anthers 1-celled! _Fert. Fl._ Ovary 3-celled, surrounded by 3 tufts of hairs (in place of a corolla). Stigmas 3, two-cleft.--Leaves linear-sword-shaped, tufted. Scape slender, bearing a single head, 2--3-angled, hairy. (Name from [Greek: la/chnos], _wool_, and [Greek: kaulo/s], _stalk_.)

1. L. Michauxii, Kunth.--Low pine-barrens, Va. to Fla.

ORDER 128. CYPERACEAE. (SEDGE FAMILY.)

_Grass-like or rush-like herbs, with fibrous roots, mostly solid stems_ (culms), _closed sheaths, and spiked chiefly 3-androus flowers, one in the axil of each of the glume-like imbricated bracts _(scales, glumes)_, destitute of any perianth, or with hypogynous bristles or scales in its place; the 1-celled ovary with a single erect anatropous ovule, in fruit forming an achene._ Style 2-cleft with the fruit flattened or lenticular; or 3-cleft and fruit 3-angular. Embryo minute at the base of the somewhat floury albumen. Stem-leaves when present 3-ranked.--A large, widely diffused family.

I. Flowers all perfect, rarely some of them with stamens or pistal abortive; spikes all of one sort.

Tribe I. SCIRPEAE. Spikelets mostly many-flowered, with only 1 (rarely 2) of the lower scales empty.

[*] Scales of the spikelet strictly 2-ranked, conduplicate and keeled.

[+] Flowers destitute of bristles and of beak to the achene, inflorescence terminal.

1. Cyperus. Spikelets few--many-flowered, usually elongated or slender.

2. Kyllinga. Spikelets 1-flowered (but of 3 or 4 scales), glomerate in a sessile head.

[+][+] Flower furnished with bristles; achene beaked; inflorescence axillary.

3. Dulichium. Spikelets 6--10-flowered, slender, clustered on an axillary peduncle.

[*][*] Scales of the several--many-flowered spikelet imbricated all round (subdistichous in n. 5).

[+] Achene crowned with the bulbous persistent base of the style (usually deciduous in n. 7); flowers without inner scales (bractlets).

[++] Hypogynous bristles (perianth) generally present; culm naked.