Vascular Plants of North Carolina
Account for Cooley's Meadow-rue - Thalictrum cooleyi   H.E. Ahles
Members of Ranunculaceae:
Members of Thalictrum with account distribution info or public map:
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Section 6 » Order Ranunculales » Family Ranunculaceae
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AuthorH.E. Ahles
DistributionLimited only to the five southeasternmost counties in the state -- Onslow, Pender, New Hanover, Brunswick, and Columbus. Within this region, most populations are in two small regions -- the northern border of Onslow and Pender counties near Maple Hill, and the area near Old Dock in eastern Columbus and western Brunswick counties.

This is a highly restricted species, found only in southeastern NC, southern GA, and the FL Panhandle. There are no records yet for SC, despite many NC records within a few miles of the state line.
AbundanceRare in the two small "nodes" mentioned above, and very rare elsewhere in these counties. This is a Federally Endangered species, with a Global Rank of G1, necessitating a State Rank of S1. Most populations are in NC.
HabitatThis species must have high pH (calcareous) soils to survive. NC populations are located over coquina/marl; specific habitats are moist to wet pine savannas and the margins of savannas with swamp forests. A few populations are in powerline clearings over marl, in sites that mimic a savanna. Sites must be burned every few years, or mowed every few years, to maintain the populations.
PhenologyBlooms in late June and early July; fruits from August to October.
IdentificationThis is a quite slender and fairly tall species, yet rather weak, and thus it normally leans on other vegetation; the stems reach 2-3 feet long. Unlike most other members of the genus, which have leaflets about as wide as long, leaflets of this species are very narrow and often unlobed. The basal leaves are usually bi-ternately to bi-pinnately dissected, with numerous leaflets (at times 20 or more), but the leaflets are mostly linear -- about 1 inch long but only averaging 1/5-inch wide. The stem leaves are often just once-pinnate, with 3 leaflets. The inflorescence typically extends far above any leaves, being a wide open panicle but with relatively few flowers. As with most others in the genus, each plant is either male or female. The sepals drop early, and there are no petals. The flowers are quite small, only about 1/4-inch across, with the filaments (male) and/or stigmas (female) being white in color, though the anthers on the male flowers are yellow, giving a nice yellow and white flower. Because the flowers are held so high off the ground, it is very difficult to obtain a photograph with both flowers and leaves! And, because this is a very slender species -- the leaflets provide little surface area -- leaning on other species, it can easily be overlooked where other tall herbaceous vegetation (2.5 feet tall or higher) is present. Needless to say, in order to see this species, you will need to visit known sites. And, it is strongly recommended to study photographs or specimens of the species before you go, to get a mental picture of what to look for.
Taxonomic CommentsNone

Other Common Name(s)Savanna Meadowrue
State RankS1
Global RankG1
State StatusE
US StatusLE
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photographercommentsphoto_linkcountyobsType
B.A. SorrieBrunswick County, 1989, Exum, NC. BrunswickPhoto_natural
B.A. SorriePender County, 2007, McLean Savanna.
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