220 



ORDER CXLI. EQUISETACEJE SCOURING RUSH-TRIBE. ORDER CXLH. FILICES FERN-FAMILY. 



more bristles, resembling awns ; otherwise as in the Panicum- 

 proper. An. 



1. S. glauca. Bottle-Grass. 



Culm erect; leaves lanceolate, rough, hairy at base; spike dense, cylindric, 

 of a dull-yellowish color when mature; bristles in clusters of 6 10, much 

 longer than the spikelets. A very common weed in waste places, distinguished 

 by its bristly, cylindrical spike. Culm 12 ft. high. July Aug. An. 



86. ANDROP6GON. 

 Spikelets in pairs at the joints of the rachis, spicate or ra- 

 cemed, one of them pedicellate, barren, often rudimentary ; the 

 other with the lower flower neutral, and consisting of a single 

 palea ; the upper perfect. Palese thin and more delicate in tex- 

 ture than the longer glumes ; lower one awned at the tip. Sta- 

 mens 1 3. Per. 



1. A. furcatus. 



Broom-Grass. 



Culms erect, branching, nearly smooth; leaves linear-lanceolate, nearly 

 smooth; radical ones very long; spikes straight, 36, hairy, digitate or clus- 

 tered at the top of the culm, or else fewer and terminating the branches, usu. 

 ally purple ; spikelets approximate, hairy, appressed ; sterile spikelets stami- 

 nate, awnless ; stamens 8. A coarse, tall grass, 46 ft. high, common in dry 

 soils, and distinguished by its digitate spikes. Sep. 



2. A. scoparius. 



Beard-Grass. 



Culm erect, slender, very branching ; branches erect, paniculate ; leaves nar- 

 row, hairy, as also the sheaths ; spikes slender, loosely -flowered, terminating 

 the branches, 2 3 from each sheath, on peduncles of various lengths, usually 

 purplish ; rachis flexuous ; pairs of spikelets remote ; sterile spikelets neutral ; 

 lower glume awned ; lower palea of the perfect flower with a twisted awn. A 

 more slender species than the last, common in sandy soils, distinguished by its 

 more slender branching stem, and its slender spikes on separate peduncles; 

 Culm 2 4 ft high. 



86. SORGHUM. 



Spikelets pedicellate, in clusters of 2 3, forming an open pa- 

 nicle ; lateral ones barren, often mere pedicels ; middle spikelet 

 fertile. Glumes coriaceous ; 2 lower flowers neutral, consisting 

 only of single palea; ; upper flower with 2 paleae, the highest of 

 which is awned at the tip. 



1. S. mUans. Indian-Grass. 



Culm erect, terete, simple ; leaves linear-lanceolate, glaucons, rough ; pani- 

 cle oblong, somewhat crowded ; perfect spikelets bright reddish-brown, at 

 length nodding, crowded toward the base with reddish hairs ; awns twisted, 

 longer than the flower ; sterile spikelets small, very imperfect, often mere hairy 

 pedicels. A coarse grass, 2 5 ft high. Common In sandy soils. Aug. Sep. 

 Per. 



2. S. saccharatum. Broom-Corn. 



Culm tall, erect, solid ; leaves lanceolate, pubescent at base ; panicle very 

 large, diffuse; branches long, slender, whorled, at length drooping; perfect 

 spikelets with hairy, persistent glumes. This well-known grass is extensively 

 cultivated for its large, branching panicle, which is used in the manufacture of 

 brooms. Culm 612 ft high. An. 



37. ZEA. 



Flowers monoecious. Barren flowers in terminal, clustered 

 racemes. Spikelets 2-flowered ; glumes 2, obtuse, nearly equal ; 

 palese obtuse, awnless. Fertile flowers lateral and axillary, densely 

 arranged on the surface of a soft, spongy, at length nearly woody, 

 round rachis, which is inclosed in an involucre of numerous bracts. 

 Spikelets 2-flowered, 1 flower abortive. Glumes 2, obtuse. Pa- 

 lese awnless. Style 1, very long, filiform, upper part pendulous 

 from the closed apex of the involucre. Grains in 3 12, usually 

 regular rows, compressed. An. 



1. Z. mays. Indian Corn. 



Culm erect, leafy, branching only at base ; leaves very long, channelled, re- 

 curved, entire, 24 ft long ; barren spikes 612, in terminal, nearly digitate 

 clusters; fertile spikes,! 4, nearly sessile, 6' 15' long, and even longer. A 

 universally esteemed grain, cultivated in almost all sections of the United States, 

 and every where in the American tropics. Culm 58 ft. high at the North, 

 1020 ft at the South. The grain varies from white to yellow, red, and even 

 blue and purple. July. 



SERIES II. Cryptogamia. 

 CLASS IIL ACROGENS. 



ORDER CXLI. Equisetaceae. Scouring 

 Rush-tribe. 



\. EQUISETUM. 



Fructification spicate. Sporangia 6 7, attached to the under 

 surface of each peltate scale, 1-celled, opening on the inner side. 

 Spores numerous, each furnished with 4 elastic filaments termed 

 elaters, which are coiled spirally around it 



1. E. limosum. 



Pipes. 



Stem tall, stout, smooth, many-furrowed, at first nearly simple, at length 

 producing simple, erect branches from above the sheaths ; spikes oblong-ovoid ; 

 sheaths appressed, with short, acute, dark-brown teeth. A tall, leafless plant, 

 28 ft. high, common in wet meadows and the borders of ponds. Most of the 

 stems bear a single, dark, terminal spike, but others are barren. All are annual 

 and greedily eaten by cattle. July. 



2. E. hyemale. Scouring Rush. 



Stems evergreen, erect, mostly entirely simple, many-furrowed, with the 

 ridges rough ; sheaths whitish, black at top and base, with subulate, quickly de- 

 ciduous teeth ; spike terminal. A stout, upright species, sufficiently distin- 

 guished by its very rough stem, which is often used in scouring metals, and by 

 its sheaths. Stem 2 3 ft, high. Common in wet grounds. June. 



3. E. arvense. Field Horse-tail. 



Stems fertile and sterile ; fertile stems brownish, bearing the spike, erect, 

 simple, with large, inflated sheaths, which have long, dark-brown teeth, appear- 

 ing early in the spring and soon decaying, followed by the sterile stems, which 

 are erect or decumbent at base, with numerous, long, simple, whorled, quadran- 

 gular, rough, green branches. A very common species in wet grounds. The 

 fertile and sterile stems are remarkably different in appearance, the one being 

 simple and brownish, and the other very branching and green. April. 



4. E. sylvaticum. 



Wood Horse-tail. 



Stems fertile and sterile ; fertile stems erect, bearing the single, pedunculate 

 spike, with a few whorls of greenish, compound, reflexed branches, which are 

 racemose with the numerous branchlets ; sterile stems as in the fertile, except 

 that they are later, and have numerous green branches. Distinguished from 

 the last by its branching fertile stems, and its whorls of deflexed branches with 

 numerous branchlets. Stem 6' 12' high. Common in wet grounds. May 



ORDER CXLII. Filices. Fern-family. 



SYNOPSIS OF THE GENERA. 



SUBORDER I. Polypodineae. 



Fronds circinate In the bud. Sporangia in dots, or in lines or clusters on the 

 back of the frond or its segments, pedicellate, the pedicel expanded above into 

 a. ring, surrounding the sporangia, which open transversely on the inner side. 

 Sori mostly inclosed while young in a membraneous covering called an INDU- 



SIUM. 



* Indusium none. 



1. PoLYpdoiUM. Sori separate, never confluent, scattered on the back of 

 the frond. 



2. STRUTBi6pTERis. Sori on a separate, fertile frond, which is much smaller 

 than the sterile, crowded, and at length confluent and covering the whole under 

 surface. 



* * Indusium present. 



t Sori strictly confined to the margin, 



3. PTEBM. Sori very narrowly linear, confluent, in a continuous marginal 

 ine. 



4. ADIANTUM. Sori roundish. Indusium reniform. Frond somewhat pe- 

 dately parted. 



6. DICKSONIA. Sori roundish, with a double indusium, one opening out- 

 ward and one opening inward. 



9. DBYdpTEKis. Sori roundish, with a single, somewhat flattened, ronndisb- 

 reniform indusium. 



1 1 Sori not confined to the margin.. 



5. AspLKNitrM. Sori linear or oblong, attached lengthwise. Indusium 

 opening lengthwise. 



