Saxifrages are basal leaved plants with a tall leafless flower stalk. The Eastern Swamp Saxifrage is a native perennial herb.

The leaves are all in a basal rosette at ground level, hairy on both sides and on the margins, fleshy, lance shaped, obtuse at the top and narrow at the base to an indistinct stalk.

Inflorescence: After the leaves develop, a hairy (purple-tipped stipitate glandular hair), 1 to 3 foot tall flower stalk emerges, on which is a "lax thyrses" - a terminal cluster of buds that looks like a pine cone, which then opens into several small branches of flower clusters. A regular thyrses is roundish compacted panicle. (See Tufted Loosestrife as an example)

The flowers can number 30 to 50+ and are 5-part, each about 1/4 inch wide, with five creamy or whitish petals, without spots, lance shaped and outward spreading. The sepals are green, more triangular and reflexed. The 10 stamens have flattened filaments and orangish color anthers creating a club shape; the ovary parts are green with two pistils with styles that are joined together for the lower half of their length. The calyx tube is nearly free from the large ovary. In a few Eastern states of the U.S. a purple-petaled version may occasionally be found.

Seed: Fertile flowers produce a dry ovoid seed capsule whose tips diverge when the small brown seeds are mature for wind dispersion.

Habitat: M. pensylvanica requires moderate moisture at a minimum, marshes and bogs preferred and does well in full to partial sun. Habitat with less moisture will need more shade. The root system has thick fleshy rhizomes which can form offsets creating more plants.

Names: Recent work with DNA evidence and differences in the ovules and the pollen has resulted in this species being moved from the Saxifrage genus to the Micranthes genus within the Saxifrage family. Micranthes is derived from two Greek words mikros meaning 'small' and anthos meaning 'flower'. The species name pensylvanica, means 'of Pennsylvania'. The accepted author names of the plant classification are: First to classify was 'L.' which refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. His work was updated by ‘Haw.’, which refers to Adrian Hardy Haworth, (1767-1833) English botanist and entomologist, Fellow of the Linnean Society, author of Lepidoptera Britannica (1803-1828) and other works including Saxifragearum enumeratio.

Comparisons: Other members of the Saxifrage Family in the garden include Alum root, Foam Flower and Mitrewort. The only other species of Micranthes found in Minnesota is Micranthes virginiensis, the Early Saxifrage. It is only found in NE Minnesota in the Arrowhead and in Lake of the Woods County where our current species is not found. It has many differences including smaller leaves and is not rhizomatous.