Plants of the Eloise Butler Wildflower Garden

Blazing Stars (also called Gayfeathers) of the Liatris genus have general characteristics of: Stem leaves narrow and lance shaped; the flower heads, typically numbering 5 to 60 (but 160+ on a few species), appear on a spike, each flowerhead containing a number of small tubular 5-lobed pink-purple florets. Local variations in species populations will be observed. Rootstocks are corms and rhizomes.

L. pycnostachya grows from 2 to 5+ feet high on erect leafy stems on which the amount of stem hair varies by the variety, of which there are two - explained below.

Leaves: There are both basal and stem leaves. Basal leaves are linear to narrowly lance shaped up to 1/2 inch wide and + or - 24 inches long. These appear in Spring long before the flowering stem appears. Stem leaves gradually but then abruptly change to linear, narrow, densely populating the stem in alternate manner and becoming bract-like near the top. Mid stem leaves can be + or - 6 inches long and upper leaves 1-1/2 inches long and 1/16 inch wide. Leaves are not hairy or glandular.

The floral array (flower area) appears as a dense spike. The spike contains a large number of densely packed flower heads without stalks. (I have counted over 160 heads on some stems.) Flower heads open from the top of the stem downward.

Flowers: Each flowerhead holds 5 to 8 florets which have pinkish purple 5-lobed tubular corollas without hair on the inside. The stamens number 5 and are united around the style part way up the corolla tube and are slightly exserted but the style is longer, deeply bifurcated and more exserted. The phyllaries around the outside of the flower head are in 4 to 5 series, generally oblong-lanceolate, unequal in size, mostly without hair, but with margins that are slightly translucent and sometimes with fine hair. Tips are pointed and curve outward to fully re-curving. Outer ones generally remain greenish, inner ones may pick up some purplish color on the tips.

Seed: The fertile flowers produce a dry seed (a cypsela), oblong, 3.8 to 4.5 mm long, ribbed, with a tawny color pappus attached for wind dispersion. Seeds require 60 days of cold stratification for germination.

Varieties: The two varieties of L. pycnostachya are var. pycnostachya, which is considered the species native to Minnesota, and var. lasiophylla. The former has stems that tend to be without hair or only sparsely hairy in the floral array with leaves that are without hair. The latter variety has stems that are moderately to densely hairy and the leaves also usually have hair.

 

Habitat: Prairie Blazing Star grows from a globose corm structure, which can produce additional plants. For good plant growth, sun and adequate moisture are required. Dry conditions will cause leaf loss and too little sun will cause twisted growth. Planting depth - the top of the corm should be 1 inch under the surface. This blazing star blooms as early as mid-July.

Names: The genus Liatris is an old name whose meaning has been lost. The species pycnostachya, is from two Greek words - pyknos, meaning 'dense' and stachys, meaning 'ear of corn' or a spike, all referring the the dense cluster of flower heads on the stem. As you can see above, a number of common names have been attached to this plant. The Garden uses the same name as USDA and the University of MN - Prairie Blazing Star - whereas Flora of North America calls it Prairie (or Cattail) Gayfeather. The MN DNR refers to it as Great Blazing Star. This is why scientific names are important.

The author name for the plant classification - ‘Michx.’ is for Andre Michaux (1746-1802), French botanist who made many exploring expeditions in the U.S. collecting and cataloging many species. Two important works were the Histoire des chênes de l'Amérique septentrionale (1801 - Oaks of North America), and the Flora Boreali-Americana (2 vols., 1803, published posthumously, and this species classification was published in this volume). His son Francois, traveled with him and the father’s notes were later used for the 3-volume North American Sylva. In earlier times this species was called Lacinaria pycnostachya.

Comparisons: Liatris pycnostachya is similar to L. spicata, except that L. spicata has more flowers per head and has rounded phyllary tips which do not curve outward. L. spicata and L. pycnostachya are difficult to distinguish without close inspection. One variety of L. spicata, var. spicata, has green phyllaries whereas a second variety, var. resinosa, has purplish phyllaries.