Ranunculus septentrionalis Poir.

Ranunculus septentrionalis plant

Family - Ranunculaceae

Stems - From fleshy roots, to 40cm tall (long), ascending, herbaceous, branching, multiple from the base, villous (the hairs spreading to slightly antrorse or retrorse and becoming appressed towards the apical end of the stems).

Ranunculus septentrionalis stem

Leaves - Alternate, petiolate, trifoliolate. Petioles to +15cm long, glabrous to pubescent, with an adaxial groove, purple to brownish at the base. Blades to +7cm long, +6cm broad. Leaflets petiolulate, 3-lobed to divided again, serrate in the apical 1/2, pubescent abaxially. Petiolules of the terminal leaflets longer than those of the lateral leaflets.

Ranunculus septentrionalis leaves

Inflorescence - Single pedunculate flowers from the upper leaf axils. Peduncles to 3cm long, antrorse strigose, angled, grooved.

Flowers - Petals 5, yellow, shiny above, dull below, rounded at the apex, glabrous, 1-1.5cm long, 7-9mm broad, with small nectaries at the base. Stamens many. Filaments yellow-green, glabrous, 2-3mm long. Anthers yellow, 1.8mm long. Receptacle pubescent. Sepals 5, yellow-green with darker green veins, spreading to reflexed, lanceolate-ovate, 8-9mm long, 3-4mm broad, pubescent externally, glabrous internally, cupped. Achenes greenish, +3mm in diameter, with a beak 2-3mm long, highly compressed, glabrous.

Ranunculus septentrionalis flower

Ranunculus septentrionalis calyx

Ranunculus septentrionalis fruitsFruits.

Flowering - April - June.

Habitat - Low ground along streams, valleys, ravines, base of bluffs, rich and moist woods.

Origin - Native to U.S.

Other info. - This is a common species throughout Missouri. It can be identified by its moist habitat and sprawling habit. The plant is, however, highly variable in it stem and leaf pubescence and may not always be easily recognized. The ascending stems and trifoliolate basal leaves are good characters to use for an identification.
Steyermark breaks the species into three varieties based on pubescence and achene size. I won't go into those here as they are no longer considered valid.
In recent taxonomy, R. septentrionalis has been absorbed into the R. hispidus complex. The three varieties mentioned by Steyermark are now varieties of R. hispidus.

Photographs taken at Eagle Bluffs Conservation Area, Boone County, MO., 4-18-04.


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