Helianthus laciniatus

A. Gray

Mem. Amer. Acad. Arts, n. s. 4: 84. 1849.

Synonyms: Helianthus crenatus R. C. Jackson Helianthus heiseri R. C. Jackson
Treatment appears in FNA Volume 21. Treatment on page 169. Mentioned on page 144.

Perennials, 50–120(–200) cm. Stems erect, usually strigose or hispid to glabrate. Leaves cauline; opposite or alternate; sessile; blades (green or grayish, 1- or 3-nerved) lanceolate, 5–9 × 0.5–3.5 cm, bases ± cuneate, margins entire or irregularly toothed to lobed, faces strigose to strumose, gland-dotted (adaxial sometimes glaucous). Heads 1–9. Peduncles 4–13 cm. Involucres hemispheric, 10–24 mm diam. Phyllaries 16–21, lanceolate, 6–7.5 × 1.8–2.5 mm (often subequal), (margins ciliate) apices acute, abaxial faces hispidulous or strigose to glabrate, gland-dotted. Paleae 7–7.8 mm, entire or 3-toothed (apices obtuse to acute, hispid-ciliate to glabrate). Ray florets 14–20; laminae ca. 8–11 mm. Disc florets 40+; corollas 4.8–5.8 mm, lobes reddish; anthers purplish, appendages reddish (style branches yellow). Cypselae 2.7–3.5 mm, glabrate; pappi of 2(–3) aristate scales 1.4–2.5 mm. 2n = 34.


Phenology: Flowering summer–fall.
Habitat: Open, dry, alkaline soils
Elevation: 1000–1200 m

Discussion

Helianthus laciniatus reaches the northern extent of its range in New Mexico and Texas; it is relatively common in the Chihuahuan Desert areas of Mexico. It is similar to H. ciliaris; it usually has hairy stems as well as denser leaf indument that includes a greater number of subsessile, glandular hairs.

Selected References

None.

Lower Taxa

None.