COMPOSITE FAMILY. COMPOSITAE.

Fig 178. [Yarrow. Milfoil. Achillea Millefolium] L.

Yarrow. Milfoil. Achillea Millefolium L. Flowers white; achenes white to gray, finely striate lengthwise, flattened, oblong, tapering at the lower end, straight or curved. 2–2.3 long. Most likely introduced from Europe.

Fig 179. [Ragweed. Ambrosia artemisiifolia] L.

Ragweed. Ambrosia artemisiifolia L. Achenes hard, straw-colored to light brown or black, top-shaped, broadly oval, 2.5–3 mm. long, besides the beak 1.5 mm. long, the sides irregularly ridged vertically, with 5–10 short teeth at the apex. Sometimes the hard covering is removed by a clover huller, exposing the naked seed. Native of the U. S.

Fig 180. [Great Ragweed. Ambrosia trifida] L.

Great Ragweed. Ambrosia trifida L. Achenes hard, brown, more or less mottled, top-shaped, 7–8 mm. besides the stout beak 2–3 mm. long, sides with 5 stout ridges terminating in 5 short teeth. Native to the United States. River bottoms, low land, sometimes 15 ft. high.

Fig 181. [Corn Camomile. Anthemis arvensis] L.

Corn Camomile. Anthemis arvensis L. Achenes very variable, creamy white to light brown, oblong, wedge-shaped in outline, circular to four-angled in cross-section, more or less ribbed lengthwise, a ripple-shaped scar at the narrow end; apex truncate with a minute projection in the center, often with a narrow ridge about the margin. About 1.7 mm. long. Introduced from Europe. Seldom troublesome in Michigan.

Fig 182. [May-weed. Dog's-Fennel. Anthemis Cotula] L.

May-weed. Dog's-Fennel. Anthemis Cotula L. Outer flowers white; achenes straw color to light brown, obovoid (large end uppermost) to oblong, circular in outline, 1.3–1.8 mm. long, with 10 warty ribs. Introduced from Europe. Old roads and waste places.

Fig 183. [Great Burdock. Arctium Lappa.]

Great Burdock. Arctium Lappa. So far as I have seen the achenes of this species, when compared with A. minus, are darker colored, rather longer, the ribs more distinct.

Smaller Burdock. Arctium minus Beruh. Possibly only a variety of A. Lappa L., but the prevailing plant in central Michigan. I see no way of distinguishing the achenes of one from the other; but it makes little difference as one burdock is as bad as another.

Flowers purple; achenes dull brown, often spotted with black, straight or curved, slightly flattened, oblong-prismatic with 3–5 narrowly ridged angles, and occasionally other smaller ridges, 4.5–6 mm. long. Introduced from Europe.

Fig 184. [Biennial Wormwood. Artemisia biennis] Willd.

Biennial Wormwood. Artemisia biennis Willd. Achenes dark brown, smooth, somewhat flattened, 3–4 angled, obovate, narrowed at the base .8–1.3 mm. long. Native in the northwestern United States and introduced east with grass seeds. Moist land.

Fig 185. [Smaller Bur-Marigold. Bidens cernua] L.

Smaller Bur-Marigold. Bidens cernua L. Flowers yellow; achenes 4–6 mm. long, dull brown, the awns lighter, flattened, 4-angled, wedge-shaped, awns 2–4, barbed downward as also are the ribs. Native of this country. Low lands.

Fig 186. [Purple-stemmed Swamp Beggar-ticks. Bidens connata] Muhl.

Purple-stemmed Swamp Beggar-ticks. Bidens connata Muhl. Flowers orange; achenes brown, wedge-shaped or obovate, hairy, tubercled, flattened, 4-angled, 4-toothed, 4–6 mm. long, achenes and teeth downwardly barbed. Swamps, common.

Fig 187. [Beggar-ticks. Bidens frondosa] L.

Beggar-ticks. Bidens frondosa L. Achenes dull brown, tubercled, much flattened, obovate or oval, 6–12 mm. long, awns usually 2, spreading barbed downward. Low lands.

Fig 188. [Star Thistle. Centaurea solstitialis] L.

Star Thistle. Centaurea solstitialis L. Achene cream white to mottled brown, flattened, oval about 2 mm. long; scar of attachment in a notch of one edge above the rounded base, apex truncate with a small tubercle in the middle. Found in seeds of alfalfa. A ragged plant from Europe.

Fig 189. [Ox-eye Daisy. Chrysanthemum Leucanthemum] L.

Ox-eye Daisy. Chrysanthemum Leucanthemum L. Flowers white; achenes brown or black with ten white conspicuous vertical ribs, narrowly obovate 1.5–1.8 mm. long, bearing a tubercle at the apex. Introduced from Europe. Becoming common. A prominent weed in old pastures and meadows.

Fig 190. [Chickory. Chichorium Intybus] L.

Chickory. Chichorium Intybus L. Flowers yellow; achenes light brown, more or less mottled or spotted with black, straight or curved, 4–5 angled, flattened, apex truncate crowned with a double row of minute scales. Achenes 2.5–3 mm. long. Introduced from Europe.

Fig 191. [Canada Thistle. Cirsium arvense] (L.) Scop. Carduus arvensis (L.) Robs.

Canada Thistle. Cirsium arvense (L.) Scop. Carduus arvensis (L.) Robs. Flowers purple or white; achenes smooth, light brown, curved or straight, narrowly obovoid or oblong, slightly flattened, 2–3 mm. long, apex truncate, cup-shaped with a tubercle in the center. Introduced from Europe. A weed of first rank.

Fig 192. [Bull Thistle. Cirsium lanceolatum] (L.) Hill. Carduus lanceolatus L.

Bull Thistle. Cirsium lanceolatum (L.) Hill. Carduus lanceolatus L. Flowers purple; achenes smooth, nearly white, with sharp vertical brown stripes, slightly flattened, obovate or oblong, usually curved near the apex, 3–4 mm. long, apex truncate with a large tubercle in the center. Introduced from Europe.

Fig 193. [Narrow leaved Hawksbeard. Crepis tectorum] L.

Narrow leaved Hawksbeard. Crepis tectorum L. Flowers yellow; achene chestnut brown, straight or curved, linear, ribs 10, smooth or rugose; 3.4 mm. long. Introduced from Europe.

Fig 194. [Fire-weed. Erechtites hieracifolia] (L.) Raf.

Fire-weed. Erechtites hieracifolia (L.) Raf. Achenes brown, linear, 2.2–2.8 mm. long, flattened, straight or curved, having ten vertical ribs between which are minute white oppressed hairs, the extremities truncate, wider than the narrow portion beneath, the apex white with a tubercle projecting from the center of a minute cup. Native to this country. Not of much importance.

Annual Fleabane. Erigeron annuus (L.) Pers. Flowers white; achenes smooth, shining, brownish white, translucent, flattened, obovate or oblong, .7-.9 mm. long, bearing at the apex a whorl of very small diverging bristles, the longest ones having been rubbed off. Faint traces of a few oppressed hairs may be seen under a good lens. Native to this country and a very prominent weed in thin meadows.

Fig 195. [Horse-weed. Erigeron Canadensis] L. Leptilon Canadense (L.) Britton.

Horse-weed. Erigeron Canadensis L. Leptilon Canadense (L.) Britton. Achenes oblong, dull cream color, much flattened, 1–1.3 mm. long, shining, smooth or containing a few minute oppressed bristles, apex truncate, bearing a whorl of bristles, the longest having been rubbed off. Native of this country. Compare the above description with that of Erigeron annuus. Common in waste places.

Fig 196. [Daisy Fleabane. Erigeron ramosus] (Walt.) B. S. P.

Daisy Fleabane. Erigeron ramosus (Walt.) B. S. P. Flowers white; achenes nearly identical with those last described, Erigeron annuus, bristles shorter, less diverging, surface bearing more minute appressed hairs when seen under a lens. Native to this country and prominent in some thin meadows.

Fig 197. [Sweet Everlasting. Gnaphalium polycephalum] Michx. Gnaphalium obtusifolium L.

Sweet Everlasting. Gnaphalium polycephalum Michx. Gnaphalium obtusifolium L. Outer scales of the head thin, white, stiff; achenes yellowish white or brown, slightly flattened, smooth, oval or oblong, .5-.7 mm. long. Native to this country. Not often troublesome.

Much practice with a good lens and careful comparisons with other small achenes will be necessary in identifying such specimens as are furnished by this species.

Fig 198. [Low Cudweed. Gnaphalium uliginosum] L.

Low Cudweed. Gnaphalium uliginosum L. Outer scales of the head thin, brown, more or less wooly; achenes .4-.6 mm. long, yellowish white to brown, slightly flattened, smooth, narrowly oblong .4-.6 mm. long. Achenes narrower and rather shorter than those of G. obtusifolium. Native to this country. Not of high rank as a weed.

Fig 199. [Broad-leaved Gum Plant. Grindelia squarrosa] (Pursh.) Dunal.

Broad-leaved Gum Plant. Grindelia squarrosa (Pursh.) Dunal. Flowers yellow; achenes creamy white or light brown, very variable in appearance, more or less flattened, often 4-angled, straight to much curved, narrowed at the base, apex truncate, often concave with a distinct marginal rim, some of them not very unlike those of Canada thistle, some of them smooth, others finely grooved or ridged lengthwise, others somewhat wrinkled, 2.5–3 mm. long. Occasionally introduced from the west with seeds of grasses or clover. Usually not persistent in Michigan.

Artichoke. Helianthus tuberosus L. Flowers yellow; achenes black, shiny more or less, slightly flattened, pubescent with very short hairs, with four obtuse angles, narrowly obovate, 6–7 mm. long, one side of the smaller end projecting beyond the other side. Native of this country; cultivated by Indians.

Fig 200. [Golden Mouse or Orange-Ear Hawkweed. Devil's Paint-Brush. Hieracium aurantiacum.]

Golden Mouse or Orange-Ear Hawkweed. Devil's Paint-Brush. Hieracium aurantiacum. Flowers orange yellow; achenes jet black, oblong, straight or curved, apex truncate, base abruptly tapering, cylindrical, the sides bearing 10 narrow, vertical ridges. Introduced from Europe. In Eastern New York and Western Massachusetts meadows abound in large areas of this vile weed, 1.8–2.2 mm. long.

Fig 201. [Mouse-Ear Hawkweed. Hieracium Pilosella] L.

Mouse-Ear Hawkweed. Hieracium Pilosella L. Flowers yellow; achenes jet black, oblong, straight or curved, apex truncate, base abruptly pointed, cylindrical or narrowly oval, the sides bearing 10 narrow vertical ridges. Introduced from Europe. The achenes very closely resemble those of the orange hawkweed. It doesn't matter much, for the habits are the same, and one is about as noxious as the other. Introduced from Europe.

Fig 202. [Elecampane. Inula Helenium] L.

Elecampane. Inula Helenium L. Flowers yellow; achenes light brown, straight or curved, linear, flattened, 4–5 mm. long, 4 sided with 5–8 obscure vertical ridges on each side, apex concave, the margin bearing a circle of short stiff bristles, the remains of longer ones. Introduced from Europe. Not common.

Fig 203. [Marsh Elder. Iva xanthiifolia] (Fresen.) Nutt.

Marsh Elder. Iva xanthiifolia (Fresen.) Nutt. Achenes various shades of brown to black, flattened or rhombic in section, obovoid, 1.5–2 mm. long, longitudinally, striate with fine lines. Native to the upper peninsula of Michigan where it most likely was at one time introduced from the west. It has not been found in the lower peninsula, probably because it had no means of coming across Lake Michigan.

Fig 204. [Wild Lettuce. Lactuca Canadensis] L.

Wild Lettuce. Lactuca Canadensis L. Flowers yellow; achenes black or nearly so, flattened, oval, bearing 3 ribs, the lateral ones sometimes double, the middle one slender, surface abounding in minute transverse ridges as seen under a lens, the remains of a beak sometimes remaining. Native of this country. Other species of Lettuce are more or less troublesome.

Fig 205.[Prickly Lettuce. Lactuca virosa] L.

Prickly Lettuce. Lactuca virosa L. For many years erroneously called Lactuca scariola. Flowers yellow; achenes dull, dark brown, mottled with black, flattened, bearing 5–7 rough, vertical ridges, interspersed by as many smaller ones; oblong, obovate, widest toward the tapering apex. 3–3.5 mm. long. Some of the leaves turn one edge up and the other down. Introduced from Europe and has proved itself a remarkable traveller.

Fig 206. [Fall Dandelion. Leontodon autumnalis] L.

Fall Dandelion. Leontodon autumnalis L. Flowers yellow; achenes light brown, linear, with 5 broad, rounded ribs; achene 4–6.5 mm. long, straight or curved, the outer traversed, with low transverse ridges. Introduced from Europe.

Fig 207. [Black-eyed Susan. Yellow Daisy. Rudbeckia hirta] L.

Black-eyed Susan. Yellow Daisy. Rudbeckia hirta L. Achene purple-brown to black, slightly tapering from base to apex 1.5–1.8 mm. long, base abruptly pointed, apex truncate, in cross section nearly square, having 5–7 slender vertical ridges on each side besides a larger one at each of the four corners. Widely distributed in meadows and pastures.

Fig 208. [Corn Sow-Thistles. Sonchus arvensis] L.

Corn Sow-Thistles. Sonchus arvensis L. Flowers yellow; achenes dull, dark reddish brown, oblong, extremities blunt, slightly flattened, bearing four coarse, fold-like ridges, with two smaller ridges between each of the two large ones, transversely wrinkled, 2.5–3 mm. long. This species is a perennial spreading by roots-stalks as well as by seeds. Introduced in Europe.

Fig 209. [Spiny Sow-Thistle. Sonchus asper] (L.) Hill.

Spiny Sow-Thistle. Sonchus asper (L.) Hill. Flowers pale yellow; achenes dull straw-color to reddish brown, much flattened, obovate, oblong, extremities blunt, each side bearing 3–5 vertical ridges, surface nearly smooth, 2.5–3 mm. long. Introduced from Europe.

Fig 210. [Common Sow-Thistle. Sonchus oleraceus] L.

Common Sow-Thistle. Sonchus oleraceus L. Flowers pale yellow; achenes reddish brown, linear, oblanceolate, 3 mm. long, flattened extremities blunt, 5 uneven wrinkled ridges on each side. Introduced from Europe.

Fig 211. [Red-Seeded Dandelion. Taraxacum erythrospermum] Andrz.

Red-Seeded Dandelion. Taraxacum erythrospermum Andrz. Achene bright red or red reddish brown, flattened, oblanceolate, 3 mm. long, 1 mm. wide or less, the red beak 1 mm. long, prickles often extending nearly to the base along twelve vertical ribs, the achenes narrower, shorter, much darker in color, with prickles extending farther down the ribs, the short beak longer; the plant is earlier, often smaller, when compared with the other species.

Doubtless this is more common than has been reported, having been overlooked. Introduced from Europe.

Fig 212.>[Dandelion. Taraxacum officinale] Weber. Taraxacum Taraxacum (L.) Karst.

Dandelion. Taraxacum officinale Weber. Taraxacum Taraxacum (L.) Karst. Flowers yellow; achenes dull light to dark brown, flattened oblanceolate, thread-like beak two to three times as long as the achene, the stout colored beak 0.5 mm. long. The most conspicuous character of the achenes lies in the barb-like-toothed edges and ridges of each of the similar faces, extending along the upper half. Achene, 3–4 mm. long, having twelve longitudinal ridges, 1.2 mm. wide. Introduced from Europe. Troublesome on thin lawns.

Fig 213. [Salsify. Oyster-Plant. Tragopogon porrifolius] L.

Salsify. Oyster-Plant. Tragopogon porrifolius L. Flowers purple; achenes dull light brown, nearly cylindrical; apex tapering, mostly terminating in a slender beak which is often longer than the body of the achene. Achene straight or curved, 10-ribbed, 12–18 mm. long, outermost coarsely roughened by upwardly directed, whitish, scale-like projections. Native of Europe.

Meadow Salsify. Yellow Goat's Beard. Tragopogon pratensis L. Flowers yellow; achenes dull, light brown, nearly cylindrical, apex tapering, mostly terminating in a slender beak. Achene straight or curved, 10-ribbed, 12–15 mm. long, the inner ones of the head smooth, the outer-most coarsely roughened by upwardly directed, whitish, scale-like projections. Introduced from Europe.

Fig 214. [American Cocklebur. Xanthium Canadensis] Mill.

American Cocklebur. Xanthium Canadensis Mill. Achenes or burs reddish brown, oblong, circular in section, two-beaked, about 20 mm. long, covered with stout hooked prickles. Each bur encloses two seeds. Native of this country.

Fig 215. [Spiny Clotbur. Xanthium spinosum] L.

Spiny Clotbur. Xanthium spinosum L. Bur oblong, light brown, very slightly flattened, 10–13 mm. long, the beaks weak and small, small hooked prickles 3–4 mm. long, each bur contains two seeds. Introduced from Europe.

Broad Cocklebur. Xanthium strumarium L. Bur dark brown, oval, circular in sections 12–22 mm. long, beaks stout, nearly straight, spines about 5 mm. long, surface of burs and base of spines clothed with minute hooked prickles. Naturalized from Europe.

INDEX.

Name,----Page

Ac-cum´bent, leaning or lying upon, applied to cotyledons when the caulicle (radicle) is folded against their contiguous edges, shown as [Symbol: 0== rotated 90 deg. clockwise].

A-chene´, achenium, a small, dry, one-seeded, indehiscent fruit, likely to be mistaken for a seed.

A-cu´min-ate, ending in a prolonged tapering point.

A-nat´ro-pous, a name applied to an ovule or seed which grows so that the funiculus coheres to the whole length forming a raphe along the edge bringing the hilum near the micropyle while the chalaza is at the other extremity.

A´pex, the tip or growing point of an organ.

Awn, a bristle-shaped appendage.

Barbed, furnished with rigid points or short bristles, usually reflexed like the barb of a fish-hook.

Car´un-cle, an excrescence or protuberance near the hilum of a seed.

Co´ma, a tuft of hair on a seed.

Del´toid, shaped like the Greek letter delta; triangular.

El-lip´tic-al, oblong and rounded at the ends; longer than oval.

Em´bry-o, the little plant forming a part of the seed, usually consisting of caulicle, one or more cotyledons and a plumule.

Fe´male flow´er, one having pistils only, but no stamens; pistillate flower.

Fer´tile, producing fruit, or reproductive bodies of any kind.

Flo´ret, a single flower of a head or cluster, especially in Compositae.

Glume, one of the outer floral envelopes in grasses or sedges. The term as now used includes the bracts (empty glumes) which subtend a spikelet and the lower of the two bracts subtending the individual flower (flowering or floral glume, lemma).

Grain, the caryopsis or fruit of Gramineae; any small seed.

Has´tate, like the head of a halberd—applied to leaves which have a spreading lobe on each side of the base.

Hi´lum, the scar or point of attachment of a seed.

In-cum´bent, leaning or lying upon; applied to cotyledons when the caulicle is folded against the track of one of them, shown as [Symbol: || o].

In-dig´e-nous, native and original to the region.

In´vo-lu-cre, a set of bracts immediately subtending a flower or inflorescence.

Keel, the joined pair of petals in a papilionaceous corolla; a projecting ridge along the back of an organ.

Lan´ce-o-late, tapering abruptly towards the base and gradually towards the apex, like the head of a lance.

Lin´e-ar, very narrow with the margins parallel or nearly so.

Ob-lan´ce-o-late, lanceolate in form, but tapering toward the base more than toward the apex.

Ob´long, longer than wide with nearly parallel sides. Compare Oval.

Ob-o´vate, a flat body broader toward the apex than the base. See Ovate.

Ob-o´void, a solid body broader towards the apex than the base. See Ovoid.

Ob-tuse´, having a rounded end or apex; blunt.

O´val, about twice as long as broad, with regular curved outlines, broadly elliptical.

O´vate, like a longitudinal section of an ordinary hen's egg, with the attachment, if any, at the broad end.

O´void, the shape of a hen's egg and attached, if at all, at the large end.

Pa´le-a, Pa´let, the upper bract which with the floral glume incloses the flower in grasses.

Pu-bes´cent, clothed with soft and rather short hairs.

Ra´phe, the adherent funiculus connecting the hilum and chalaza in anatropous or amphitropous ovules or seeds.

Re-tic´u-late, in the form of network.

Root, the descending axis which is destitute of leaves or nodes.

Root stock, rhizome, a stem usually subterranean and more or less thickened, producing young branches.

Spike´let, a small or secondary spike, as found in grasses.

Ster´ile, not fertile.

Stri´ate, striped with parallel ridges and grooves.

Trun´cate, terminating abruptly, as though cut off or flattened at the end. Compare Premorse and Succise.

Tu´ber-cle, a swollen part or a root due to bacteria. Usually applies to such as possess the power to fix nitrogen; a little tuber.

☞ If not familiar with the decimal scale used in recording measurements in this volume, the reader can clip out one of those found below and use it for measuring.