''Thalictrum dioicum'', the early meadow-rue or quicksilver-weed, is a species of herbaceous plants in the family

Ranunculaceae Ranunculaceae (buttercup or crowfoot family; Latin "little frog", from "frog") is a family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are ''Ranunculus'' (600 species), ''Delphinium' ...

. Plants are typically upright growing

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

natives from Colorado Rocky Mountain forests to central and eastern North America including parts of south eastern Canada. This species has dioecious plants, with male and female flowers on separate plants blooming in early to mid spring. ''Thalictrum dioicum'' grows from 30 to 80 cm tall, from upright

caudex A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is m ...

, with yellow-gold colored – thick fibrous roots. New caudexes are generated each year by the current years plant and the old caudex withers away in the fall and early spring of the next year. In early spring plants grow, producing glabrous or glandular leaves. both basal and cauline leaves are produced that have long petioles. Leaf blades are 1-4×-ternately compound with leaflets reniform or cordate to obovate or orbiculate in shape. The leaflets are 10–45 mm wide with lobed margins often crenate, and the undersides are normally glabrous or glandular.

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

s are

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

s or

corymb Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficial re ...

s produced terminally and axillary with many flowered branches. The flowers have no petals but have greenish colored, 1.8–4 mm long sepals sometimes tinted purple. The sepals are ovate to obovate or oval in shape. On male plants, the flower filaments are the most showy part of the hanging flowers, being yellow to greenish yellow in color and 3.5-5.5 mm long. The filaments end in anthers 2–4 mm long that are

mucronate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

acuminate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

in shape with purple colored stigma. After blooming, female plants if fertilized, produce green fruits called

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

s. Each flower that is fertilized typically produces (3-)7 to 13 achenes that are not reflexed and sessile or nearly so in tight clusters. The achenes are ovoid to ellipsoid in shape and not laterally compressed, 3.5–5 mm long, glabrous, very strongly veined, with 1.5 to 3 mm long beaks, ripening in mid summer. Plants are grown in shade gardens for their attractive lacy foliage that is reminiscent of columbines or maiden hair fern. The males produce more showy flowers than the female plants, blooming in early spring with the flowers and foliage rising out of the ground in club-like clusters with the basal leaves unfolding first. Plants start to flower before the compound leaves have completely unfolded. This species, like some others of its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

, is pollinated via wind action (

anemophily Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including grasses, sedges, and rushes. Other common anemophilous plan ...

). Males start off the year taller than the females, but as the fruits grow females are taller typically in summer.

References

External links

* *
Flora of Pennsylvania
{{Taxonbar, from=Q7709654 dioicum Flora of the Eastern United States Flora of Eastern Canada Flora of the Northeastern United States Flora of the Southeastern United States Flora of the Appalachian Mountains Flora of the Rocky Mountains Plants described in 1753 Taxa named by Carl Linnaeus Dioecious plants