Liatris mucronata DC.

Narrow-leaved Gayfeather

© SRTurner

Family - Asteraceae/Eupatorieae

Habit - Perennial forb from a more or less globose corm.

Stem - Ascending to erect, to 90 cm, usually multiple from the base, glabrous.

	Lower stem and nodes.
© SRTurner

	Mid-upper stem and nodes.
© SRTurner

Leaves - Alternate, simple. Basal and adjacent lower stem leaves sessile to short-petiolate, the blades 7-15 cm long, 1-4 mm wide, linear, the narrow, light margins occasionally curled under, the surfaces glabrous, green, with 1 main vein, grading toward the stem tip to shorter leaves, these mostly sessile, 1.5-12.0 cm long, linear.

	Leaves.
© SRTurner

	Mid-lower leaf, adaxial.
© SRTurner

	Mid-lower leaf, abaxial.
© SRTurner

	Leaf abaxial surface.
© SRTurner

Inflorescence - Elongate spikes, the heads densely spaced (the axis mostly not visible between heads), sessile or nearly so, with 1 basal bract.

	Inflorescence.
© SRTurner

Heads - Discoid. Heads with 3-6 disc florets, the terminal head sometimes slightly longer than the others. Involucre 7-12 mm long, narrowly cupshaped to nearly cylindrical, with 4-6 unequal, overlapping series of bracts (the outer series appearing somewhat shorter). Involucral bracts broadly lanceolate to narrowly oblong-obovate, tapered to a sharply pointed, ascending to somewhat spreading tip, mostly with narrow, thin, pale to transparent margins, these sometimes slightly to strongly purplish-tinged, more or less entire but sometimes cobwebby-hairy, the main body appearing flat below the tip.

	Heads.
© SRTurner

	Head.
© SRTurner

Flowers - Ray florets absent. Disk florets with the corollas 9-11 mm long, glabrous or the tube sparsely hairy on the inner surface toward the base, purple. Pappus bristles plumose.

	Florets.
© SRTurner

	Florets. The pappus bristles are plumose, but this character is difficult to evaluate reliably in the field.
© SRTurner

	Pappus bristles are plumose (featherlike). This character is difficult to evaluate in the field. It is most readily observed with florets or achenes which are partially dried, with the pappus bristles spread apart.
© SRTurner

Fruits - Achenes 5.5-7.5 mm long.

Flowering - July - October.

Habitat - Glades and bluffs, on limestone and dolomite substrates.

Origin - Native to the U.S.

Lookalikes - Liatris punctata, L. pycnostachya.

Other info. - This relatively uncommon member of the Liatris genus is found in a handful of counties in the southern part of the state. Beyond Missouri its range extends in a band from eastern Kansas southward through Texas, nearly to the Gulf Coast. It is easily identified as a Liatris by its spikes of small purple florets which are contained in heads. The heads are crowded, such that the inflorescence axis is generally not visible. The plant most closely resembles L. punctata, and in fact is considered a variety of that species by some authors. The leaves of L. mucronata are glabrous whereas those of L. punctata usually have some hairs on the margins. There are also differences in the rootstocks, and the ranges of the two species in Missouri do not overlap. Nevertheless, the two can be difficult to distinguish in some cases.

Photographs taken at Glade Top Trail National Scenic Byway, Ozark County, MO, 8-16-2023 (SRTurner).