Thalictrum thalictroides (Rue-anemone) is a spring

Spring (season)

Spring is one of the four temperate seasons, the transition period between winter and summer. Spring and "springtime" refer to the season, and broadly to ideas of rebirth, renewal and regrowth. The specific definition of the exact timing of "spring" varies according to local climate, cultures and...

 ephemeral

Ephemeral Plant

An ephemeral plant is one marked by short life cycles, usually six to eight weeks. The word ephemeral means transitory or quickly fading. In regards to plants, it refers to several distinct growth strategies...

 plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 in the buttercup family

Ranunculaceae

Ranunculaceae are a family of about 1700 species of flowering plants in about 60 genera, distributed worldwide....

, prized for its white to pink flowers, native to woodland

Woodland

Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

 in eastern North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

.

Description

T. thalictroides is a hairless plant growing from tuber

Tuber

Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...

ous roots, with upright 10-30 cm tall, stem

Plant stem

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

s which end with flowers. The basal leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 have 10 to 30 cm long petiole

Petiole (botany)

In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...

s and leaf blades that are 2×-ternately compound. The leaflet

Leaflet

A leaflet in botany is a part of a compound leaf. A leaflet may resemble an entire leaf, but it is not borne on a stem as a leaf is, but rather on a vein of the whole leaf. Compound leaves are common in many plant families...

s are widely rounded in shape and the ends are three lobed

Lobe (anatomy)

In anatomy, a lobe is a clear anatomical division or extension that can be determined without the use of a microscope This is in contrast to a lobule, which is a clear division only visible histologically....

.

It flowers in early spring and the flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s are borne singularly, or in umbel

Umbel

An umbel is an inflorescence which consists of a number of short flower stalks which are equal in length and spread from a common point, somewhat like umbrella ribs....

-like inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

s with 3 to 6 flowers. The flowers have short stems that hold the fully opened flowers above the foliage. The involucral bract

Bract

In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...

s are 3-foliolate, and shaped like the leaves. The showy rounded flowers have many yellow stamen

Stamen

The stamen is the pollen producing reproductive organ of a flower...

s in the middle, and a cup of white to pinkish-lavender sepal

Sepal

A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...

s.

In late spring, 3 to 4.5 mm long, ovoid to fusiform shaped fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

s called achene

Achene

An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...

s are released. The green achenes have 8 to 10 prominent veins and become dark brown when ripe.

Taxonomy

Originally described as Anemone thalictroides by Linnaeus in 1753. It was transferred to a new, monospecific genus, Anemonella, by Édouard Spach in 1839. Although similar to plants in the genus Thalictrum, Sprach considered the diminutive size, umbelliform inflorescence, and tuberous roots of this species to be distinctive enough to designate a new genus. JRB Boivin considered this distinction suspect, and transferred the species to the genus Thalictrum in 1957. Molecular evidence supports the placement of the species within Thalictrum, and this placement is accepted by several modern treatments.