Helianthus maximiliani
Helianthus schweinitzii
hélianthe de maximilien, Maximilian sunflower, Maximilian's sunflower
Schweinitz's sunflower
erect, 5–30 dm, scabrous to scabro-hispidulous.
(often reddish, leafy) erect, ± strigose proximally, strigose or glabrous distally.
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.
cauline; opposite (proximal) or alternate;
petioles 0–1 cm;
blades (light to dark green, 3-nerved distal to bases) lanceolate to lance-linear, 6–18 × 1–2 cm, bases cuneate, margins entire or subentire (revolute), faces hirsute to tomentose and gland-dotted (abaxial) or scabrous (adaxial).
1–11 cm.
1.5–8 cm (not gland-dotted).
hemispheric, 13–28 mm diam.
hemispheric, 9–10(–16) mm diam.
10–25;
laminae (15–)25–40 mm.
8–15;
laminae 15–22 mm (abaxial faces gland-dotted).
75+;
corollas 5–7 mm, lobes yellow;
anthers dark brown or black;
appendages usually yellow, sometimes partly dark.
40+;
corollas 5–6 mm, lobes yellow;
anthers dark brown to black, appendages dark or reddish brown.
30–40, lanceolate, 14–20 × 2–3 mm, (margins ciliate) apices acute to attenuate, abaxial faces canescent, gland-dotted.
16–20 (reflexed or loose), lanceolate or lance-ovate, 5–7 × 1.5–2.3 mm, apices acute to acuminate, abaxial faces hirsute (proximally) to glabrate, gland-dotted.
(1–)3–15 (often in racemiform to spiciform arrays).
3–6.
3–4 mm, glabrate;
pappi of 2 aristate scales 3–4.1 mm.
3–4 mm, glabrate;
pappi of 2 aristate scales 1.5–2 mm.
7–11 mm, entire or 3-toothed (apices greenish, mucronate, hairy).
5.5–6.5 mm, 3-toothed (apices hairy).
= 34.
= 68.
Helianthus maximiliani
Helianthus schweinitzii
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Helianthus schweinitzii is distinguished by its relatively small heads and sessile to subsessile, narrowly lanceolate leaves with revolute margins. Chromosome number, typification issues, and identification of voucher specimens were updated by J. F. Matthews et al. (1997).
Helianthus schweinitzii is found on the Carolina piedmont. It was listed as endangered in the Federal Register on May 7, 1991, and is known from 16 populations. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC - Local Web sites:
CalFlora, CalPhotos, 
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
