44.
Helianthus maximiliani
Schrader, Index Seminum (Göttingen). 1834: unpaged. 1835.
Maximilian sunflower , hélianthe de Maximilien
Helianthus dalyi
Britton
Perennials
, 50—300 cm (rhi-zomatous).
Stems
erect, 5—30 dm, scabrous to scabro-hispidulous.
Leaves
cauline; mostly alternate; petioles 0—2 cm; blades (light green to gray-green, 1-nerved, conduplicate) lanceolate, 10—30 × 2—5.5 cm, bases cuneate, margins usually entire, sometimes serrulate, abaxial faces scabrous to scabro-hispid, gland-dotted.
Heads
(1—)3—15 (often in racemiform to spiciform arrays
). Peduncles
1—11 cm.
Involucres
hemispheric, 13—28 mm diam.
Phyllaries
30—40, lanceolate, 14—20 × 2—3 mm, (margins ciliate) apices acute to attenuate, abaxial faces canescent, gland-dotted.
Paleae
7—11 mm, entire or 3-toothed (apices greenish, mucronate, hairy).
Ray florets
10—25; laminae (15—)25—40 mm.
Disc florets
75+; corollas 5—7 mm, lobes yellow; anthers dark brown or black; appendages usually yellow , sometimes partly dark
. Cypselae
3—4 mm, glabrate;
pappi
of 2 aristate scales 3—4.1 mm.
2
n
= 34.
Flowering late summer—fall. Prairies , fields, waste areas; 0—300(—2100+) m; Alta., B.C., Man., Ont., Que., Sask.; Ala., Ark., Calif., Colo., Conn., Del., D.C., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Utah, Va., Wash., W.Va., Wis., Wyo.; Mexico.
Helianthus maximiliani
is introduced in eastern Ontario and in Quebec. It appears to be native to midcontinental prairie regions and has spread along railroads and highways into all areas of North America. Its wide dispersal may be aided by cultivation for its attractive, showy floral displays. In addition to the usually conduplicate, single-nerved leaves and spikelike arrangement of the heads, it is distinguished by the whitish-canescent indument of the leaves and stems and the long-attenuate phyllaries.
