Helianthus pauciflorus ssp. subrhomboideus (Beautiful Sunflower) - photos and description

Helianthus pauciflorus ssp. subrhomboideus

Helianthus pauciflorus ssp. subrhomboideus

Helianthus pauciflorus ssp. subrhomboideus

Helianthus pauciflorus ssp. subrhomboideus
Leaf mid-stem

Helianthus pauciflorus ssp. subrhomboideus
Lowest stem leaves sometimes spatulate

Helianthus pauciflorus ssp. subrhomboideus

General: Perennial plants with simple stems. Stems rough hairy below, less hairy at the top.

Flowers: Flower heads single on long peduncles, flowers few - we observed 1to 3 flower stems at top of plants. Flower heads measured to 25 mm diameter, disk dark brown or a bit purplish in colour. Ray florets measured to 25 mm long. Bracts lanceolate to ovate, measured to 7 mm long. 

Leaves: Leaves opposite, all cauline, lowest leaves sometimes spatulate, leaves reduced upwards. Leaves mid-stem and lower with petioles, upper leaves sessile. Sharp, shallow teeth on larger, lower leaves; upper leaves usually entire. Leaves rhombic-ovate to rhombic-lanceolate. Stem leaves often noticeably 3-nerved. Leaves to 10 cm long. Leaves rough-hairy both sides and ciliate.

Height: Height listed in Budd's Flora to 100 cm, we measured plants to 114 cm tall.

Habitat: Moist grassland.

Abundance: Common.

Origin: Native.

Synonyms: Listed in some of the field guides we use as Helianthus subrhomboideus, H. rigidus, and H. laetiflorus var. subrhomboideus.

How to identify this species of Helianthus: Perennial, central disk brown, leaves all opposite (Taxonomic Reminder for Identifying Saskatchewan Plants).

When and where photographed: The above photos were taken August 5th, prairie hillside, Buffalo Grass Eco Reserve, 200 km south east of our home in Regina, SK.