Part 6

=Squirrel-tail Grass.= Hordeum jubatum L. Spikelets in clusters of three, central one only fertile, 5 mm. long, containing a grain adhering to the floral glume and palea, the other two abortive, seven awns in these three spikelets, 4-6 cm. long, four others less than 1 cm. long; awns and fragment of rachis holding the cluster of spikelets together, all barbed upward, making them troublesome for fleeces of sheep and the mouths of animals eating them. Native of this country and widely distributed.

=Old Witch Grass. Tickle Grass. A Tumble-Weed.= Panicum capillare L. Florets flattened, elliptical, apex abruptly pointed, about 1.5 mm. long, highly polished, leaden gray, lighter at the extremities and along the edges of the glume, five slender light colored nerves join the extremities passing vertically over the glume, two light nerves on the palea. Native to this country.

=Tall Smooth Panicum. Switch Grass.= Panicum virgatum L. Achene surrounded by two persistent shining pieces, the floret; floral glume hard, light brown, oval or ovate-lanceolate 2.5-3.1 mm. long. Apex obtusely pointed. Seldom troublesome, widely distributed.

=Low Spear-Grass.= Poa annua L. Florets straw-colored, 2.8-3.1 mm. long, apex smooth, lower half of keel and the base of lateral nerves, having numerous soft hairs. A low annual grass, introduced from Europe.

=Flat stemmed Poa. Wire Grass. Canadian Blue Grass.= Poa compressa L. Florets lance-obovate, 2-2.5 mm. long, closely resembling those of Poa pratensis, which see.

Palea abruptly acute. If well rubbed after threshing, the floret is nearly smooth, otherwise it contains on the lower half numerous webby hairs. Grain reddish brown, both ends pointed, 1-1.4 mm. long. Seldom sown purposely. Sometimes used to adulterate Poa pratensis. In early days this grass was called blue grass by people of New England and New York State. Introduced from Europe.

=June Grass. Kentucky Blue Grass.= Poa pratensis L. Florets ovate-lanceolate, acute 3-4 mm. long, with three equal sides when seen in transverse section, nearly smooth, if severely rubbed in threshing, otherwise the floral glume is thickly webbed at the base; palea acuminate, grain light brown, elliptical, both ends usually pointed 1.2-1.4 mm. long, in cross sections with three equal sides, one of which has a shallow vertical groove. Compare with Poa compressa. Introduced from Europe.

=Rye.= Secale cereale L. Grain light brown, 6-8 mm. long, elliptical, base acute, apex obtuse and rounded, in cross section the back somewhat acutely rounded, the opposite side with a narrow vertical groove, surface more or less irregularly wrinkled. Introduced from Europe. A bad weed in wheat fields.

=Pigeon-Grass. Yellow Foxtail.= Setaria glauca (L.) Beauv. Chaetochloa glauca (L.) Scrib. Spikelets light to dark brown, 2.5-3 mm. long; after threshing or much rubbing consisting of each a grain and two firm coverings, known as a floral glume which covers the sides of the somewhat depressed palea, oval, apex slightly 3-toothed, rounded side strongly arched, somewhat V-shaped, roughened crosswise by prominent fine more or less branching ridges; ridges of palea on concave side less prominent. Introduced from Europe. Very common in hoed annual crops.

=Green Foxtail. Green Pigeon Grass.= Setaria viridis (L.) Beauv. Chaetochloa viridis (L.) Nash. Spikelets, light to dark brown mottled, 2-2.3 mm. long, after threshing or much rubbing consisting of the grain and two firm coverings, the rounded one known as a floral glume which covers the edges of the flattened side, oval, the surface granular and very faintly striate, lengthwise and ridged crosswise. Much resembling Hungarian grass. Introduced from Europe. Found with yellow foxtail.

=Porcupine Grass.= Stipa spartea Trin. Grain inclosed in the floral glume, light brown, 18 mm. long, clothed on the lower half with short brown hairs slanting upward, bearing at the base a sharp, hard, curved beak, when dry the attached awn is twisted for 6 cm. and straight and bent at right angles about 6 cm. When moistened, the awn untwists more or less; twisting and untwisting the beards hold what the beak pierces, thus making it a formidable weapon to enter the skins of sheep, goats and dogs. Fortunately it is seldom abundant. Sandy land Michigan and westward.

SEDGE FAMILY. CYPERACEAE.

=Yellow Nut-Grass.= Cyperus esculentus L. This is a species of sedge, and so far as I have examined, produces no seeds, perhaps having lost that method of reproduction, as it acquired the habit of spreading by tubers here illustrated. In moist soil, sometimes a troublesome weed.

=Ovoid Spike-rush.= Eleocharis ovata (Roth.) R. & S. Spike ovoid, 4-10 mm. long, achene pale to chestnut brown, shining, obovate-oblong, compressed, about 1 mm. long, bearing a triangular tubercle at the apex, and six to eight barbed bristles, 1.3-1.7 mm. long, very variable. Not troublesome except in low land.

RUSH FAMILY. JUNACEAE.

=Slender Rush.= Juncus tenuis Willd. Seeds light brown to amber color, translucent, flattened, oval, half oval, oblong, ovoid, the acute apex curved to one side, about 0.3 mm. long. Dry to moist soil, almost throughout North America, now migrating to all parts of the world. A very common, grass-like rush in this state, seldom recognized by any one under any name, except by a first-rate botanist.

LILY FAMILY. LILACEAE.

=Field Garlic. Wild Garlic.= Allium vineale L. Seeds not seen, apparently seldom produced; bulblets (b) light yellow or almost white, obovoid to elliptical, 7-8 mm. long, when dry. Introduced from Europe. Troublesome in pastures and tainting the flavor of butter; in wheat it taints the flavor of flour. Persistent when introduced. The illustration of grains of wheat (a) are given for comparison.

NETTLE FAMILY. URTICACEAE.

=Slender Nettle.= Urtica gracilis Ait. Achenes compressed, lens-shaped, ovate, rarely oval, faces similar, smooth, dull and grayish brown, .9-1.1 mm. long. Native of this country. Compared with U. dioica, this achene is thinner and shorter. Prominent in low pastures.

BUCKWHEAT FAMILY. POLYGONACEAE.

=Knot-Grass.= Polygonum aviculare L. This door-yard weed is in no sense a grass. Achenes unequally 3-sided, ovoid, acute, angles obtuse, surface, dull, light to dark reddish brown, finely granular and striate lengthwise. 1.8-2.2 mm. long, usually with the remains of calyx attached. Native of this country. Common about door-yards.

=Wild Buckwheat.= Polygonum Convolvulus L. Achenes dull, jet-black, equally 3-sided, elliptical to obovoid, minutely granular often with faint longitudinal striation, the faces often more or less concave, the angles rounded, 2.5-3.5 mm. long, sometimes with the remains of calyx attached. Introduced from Europe. Often climbing up corn stalks.

=Erect Knotweed.= Polygonum erectum L. Achenes dull, light to dark brown, unequally 3-sided, ovoid or rhombic, finely granular and striate lengthwise, the faces sometimes concave, the angles rounded, 2.5-3 mm. long, sometimes with the remains of calyx attached. Native to this country. Of little account.

=Smart-weed.= Polygonum Hydropiper L. Achene dull, granular, light to dark reddish brown, lenticular, acutely and narrowly or broadly elliptical, or 3-sided, apex acute, concave on the sides, angles obtuse, 2-3 mm. long, sometimes with the remains of the dotted calyx attached. Introduced from Europe. Wet land.

=Dock-leaved or Pale Persicaria.= Polygonum lapathifolium L. Achene shining, dark to chestnut brown, 2-2.2 mm. long, flattened, circular to broadly ovate with abruptly pointed apex, the base obtuse or bearing the remains of the thin calyx. Introduced from Europe. Low wet places.

=Shore Knotweed.= Polygonum littorale Link. So far as the achenes are concerned, they are identical with those of P. aviculare above described. Native of this country. On hard or thin places, especially when newly graded.

=Pennsylvania Persicaria=, Polygonum Pennsylvanicum L. Achene shining, jet-black, flattened, surface very slightly uneven and granular nearly circular with a short abrupt apex, edge rounded, 2.5-3 mm. long, often bearing the remains of the calyx. Native to this country. Occasional in annual crops.