. A manual of weeds : with descriptions of all the most pernicious and troublesome plants in the United States and Canada, their habits of growth and distribution, with methods of control . Weeds. COMPOSITAE {COMPOSITE FAMILY) 545 filled with bitter, milky juice. Heads in open racemes, lifted on rather long, scaly-bracted peduncles; they are about an inch broad, with numerous light blue rays, toothed at the tips; bracts of the involucre imbricated in three or four rows, the inner ones lance-shaped, the outer ones shortening to pointed ovate. Achenes flattened club-shaped, with ridged margins a
. A manual of weeds : with descriptions of all the most pernicious and troublesome plants in the United States and Canada, their habits of growth and distribution, with methods of control . Weeds. COMPOSITAE {COMPOSITE FAMILY) 545 filled with bitter, milky juice. Heads in open racemes, lifted on rather long, scaly-bracted peduncles; they are about an inch broad, with numerous light blue rays, toothed at the tips; bracts of the involucre imbricated in three or four rows, the inner ones lance-shaped, the outer ones shortening to pointed ovate. Achenes flattened club-shaped, with ridged margins and finely grooved sides, tapering to a short, stiff beak tipped with a cup-like disk to which is at- tached a copious, silky, white pappus which enables the winds to sow the seed very widely. (Fig. 378.) Means of control On the first appearance in any locality, it will pay to hand-pull or dig out the plants before seed production and before the rootstocks have penetrated far into the soil. Established root- stocks should be starved by persistent close cutting of all leaf-growth throughout the growing season. Where the land is badly infested, short rotations of cultivated crops — with very thorough tillage — are necessary if the weed is to be subdued. HAIRY-VEINED BLUE LETTUCE Lactiica villdsa, Jacq. Native. Biennial. Propagates by seeds. Time of bloom: July to September. Seed-time: August to October. Range: New York to Illinois and Nebraska, southward to Georgia, Florida, and Kentucky. Habitat: Meadows, pastures, fence rows, and borders of woods. Stem two to six feet tall, round and smooth. Leaves oblong to lance-shaped, long-pointed, light green, smooth and glossy above but set with stiff bristly hairs on midrib and veins beneath, sharply and often doubly toothed, the lower ones usually lobed at the base 2n. Tig. 378. — Blue Lettuce (Lactuca pulcheUa). X Please note that these images are extracted from scanned page images that may have been digitally enhanced for rea
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectweeds, bookyear1919
