Thalictrum cooleyi

H. E. Ahles

Brittonia 11: 68. 1959.

Common names: Cooley's meadow-rue
Conservation concernEndemicIllustrated
Treatment appears in FNA Volume 3. Treatment on page 270.

Stems erect to reclining, slender, 60-200 cm. Leaves: proximal cauline petiolate, distal cauline sessile to nearly sessile; petioles and rachises glabrous, neither pubescent nor glandular. Leaf-blade: proximal cauline mostly 2×-ternately compound, distal cauline usually ternately compound; leaflets linear to narrowly lanceolate or oblanceolate, apically occasionally 2-3-lobed, 12-68 × 1-12 mm, length (2.6-) 4-26 times width, membranous to leathery, margins sometimes revolute, lobe margins entire; surfaces abaxially glabrous. Inflorescences racemes to panicles, elongate, few flowered; peduncles and pedicels neither pubescent nor glandular. Flowers usually unisexual, staminate and pistillate on different plants; sepals 4-5, white to yellowish in staminate flowers, greenish in pistillate flowers, obovate, 1.5 mm; filaments white to purple, 2.5-6 mm; anthers 0.9-2.5 mm. Achenes 5-6, sessile or nearly sessile; stipe 0-0.4 mm; body ellipsoid, 4.5-6 mm, prominently veined, glabrous; beak 1.3-2.4 mm. 2n = 210.


Phenology: Flowering summer (mid Jun-mid Jul).
Habitat: Boggy, savannahlike borders of low woodlands, and disturbed areas such as roadside ditches, clearings, and edges of frequently burned savannahs

Discussion

Of conservation concern.

Thalictrum cooleyi occurs commonly on Grifton soil and is associated with some sort of disturbance, including clearings, edges of frequently burned savannahs, roadsides, and powerline rights-of-way that are maintained by fire or mowing. Silvicultural and agricultural practices and their associated suppression of fire have seriously affected populations of T. cooleyi. Furthermore, fruit production appears to be quite low in the species (S. W. Leonard 1987).

Leaves of Thalictrum cooleyi have fewer leaflets than other species of Thalictrum sect. Leucocoma.

Selected References

None.

Lower Taxa

None.

"glabrous" is not a number.

... more about "Thalictrum cooleyi"
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Marilyn M. Park +  and Dennis Festerling Jr. +
H. E. Ahles +
cuneate +, truncate +  and cordate +
Leucocoma +  and Undefined sect. Leucocoma +
straight +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
ellipsoid +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
globose;cylindric +
Cooley's meadow-rue +
sessile +  and nearly sessile +
Fla. +  and N.C. +
white +  and purple +
filiform +  and clavate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
pistillate +  and staminate +
showy +  and inconspicuous +
unisexual +
0 cm0 mm <br />0 m <br /> (41 cm410 mm <br />0.41 m <br />) +
stipitate +, sessile +  and aggregate +
falcate;ovoid;obovoid +
Boggy, savannahlike borders of low woodlands, and disturbed areas such as roadside ditches, clearings, and edges of frequently burned savannahs +
cauline +  and proximal +
compound +  and simple +
whorled +, opposite +  and alternate +
cauline +  and basal +
1.2 cm12 mm <br />0.012 m <br /> (6.8 cm68 mm <br />0.068 m <br />) +
2-3-lobed +, linear +  and narrowly lanceolate or oblanceolate +
membranous +  and leathery +
0.1 cm1 mm <br />0.001 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
palmate +  and pinnate +
crenate;entire +
(1-)2-200-flowered +
distinct +
conspicuous +
spurred +, funnel--shaped +, cup-shaped +  and plane +
reduced +
pubescent;glabrous +
Flowering summer (mid Jun-mid Jul). +
1 +  and 16 +
pubescent;glabrous +
not arillate +  and stalked +
greenish;white;yellowish +
not persistent +
distinct +
4 +  and 5 +
obovate +
1.5 cm15 mm <br />0.015 m <br /> (?) +
ribbed +  and veined +
Conservation concern +, Endemic +  and Illustrated +
erect +  and reclining +
slender +
60 cm600 mm <br />0.6 m <br /> (200 cm2,000 mm <br />2 m <br />) +
0 cm0 mm <br />0 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
persistent +
Thalictrum cooleyi +
Thalictrum sect. Leucocoma +
species +
herbaceous +  and woody +