. An illustrated flora of the northern United States, Canada and the British possessions, from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian. Botany; Botany. Gexus 34. THISTLE FAMILY. 435 34. MACHAERANTHERA Xees, Gen. & Sp. Ast. 224. 1832. Annual, biennial or perennial branched herbs, with leafy stems, alternate, mostly serrate or pinnatifid leaves, the teeth or lobes usually bristle-tipped, and large heads of both tubular and radiate flowers. Involucre of numerous series of imbricated canescent or glandular bra
. An illustrated flora of the northern United States, Canada and the British possessions, from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian. Botany; Botany. Gexus 34. THISTLE FAMILY. 435 34. MACHAERANTHERA Xees, Gen. & Sp. Ast. 224. 1832. Annual, biennial or perennial branched herbs, with leafy stems, alternate, mostly serrate or pinnatifid leaves, the teeth or lobes usually bristle-tipped, and large heads of both tubular and radiate flowers. Involucre of numerous series of imbricated canescent or glandular bracts with herbaceous or foliaceous spreading or appressed tips. Receptacle alveolate, the alveoli usually toothed or lacerate. Ray-flowers numerous, violet to red or purple, pistillate. Disk-flowers perfect, their corollas tubular, 5-lobed, yellow, changing to red or brown; anthers exserted, appendaged at the tip, rounded at the base; style-appendages subulate to lanceolate. Achenes turbinate, narrowed below, pubescent. Pappus of numrous stiff, rough unequal bristles. [Greek, sickle-anther.] About 15 species, natives of western Xorth America. Type species: Machaeranthera tanaceti- folia () Xees. Annual or biennial; leaves pinnatifid. i. J/, tanacetifolia. Perennial or biennial; leaves sharply serrate. 2. M. sessiliflora. i. Machaeranthera tanacetifolia () Xees. Tansy Aster. Dagger-flower. Fig- 4359- Aster tanacetifolius Nov. Gen. Sp. 4: 95. 1820. it. tanacetifolia Xees, Gen. & Sp. Ast. 225. 1832. Annual or biennial; stem glandular-pubescent, often viscid, densely leafy, much branched and bushy, i°-2° high. Leaves sessile or short-petioled, pubescent, the lowest i'-3' long, 2-3-pinnatifid, their lobes linear or oblong, acute or mucronate, the up- per pinnatifid, those of the branches sometimes en- tire; heads numerous, corymbose-paniculate, 1-2' broad; involucre hemispheric, 4"-6" high, its bracts linear, glandular, imbricated in 5-7 series, thei
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
