Thalictrum texanum

(A. Gray) Small

Fl. S.E. U.S., 446. 1903.

Conservation concernEndemic
Basionym: Thalictrum debile var. texanum A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1: 18. 1895
Treatment appears in FNA Volume 3.

Roots becoming black when dry, tuberous, not ribbed, irregular. Stems erect, 10-45 cm, rigid, glabrous. Leaves: distal cauline long-petiolate. Leaf-blade 2×-ternately compound; leaflets cuneate to reniform, undivided, cleft, or lobed, 2-7 mm wide, margins entire or sometimes weakly crenate, surfaces glabrous, somewhat glaucous. Inflorescences terminal, racemes, several flowered. Flowers: sepals lanceolate to obovate, in staminate flowers 1.7-3 mm, in pistillate flowers 0.7-1.5 mm; filaments colored, not white, ca. 1.5 mm; anthers 1.4-2 mm; stigma color unknown. Achenes few, not reflexed, nearly sessile; stipe 0.1-0.3 mm; body ovoid, not laterally compressed, adaxial surface 2.7-3.7 × 1.4-1.6 mm, glabrous, prominently 6-8-veined, veins not anastomosing-reticulate; beak 0.5-1 mm.


Phenology: Flowering early spring (Mar–Apr).
Habitat: Margins or openings of mesic woodlands or forests
Elevation: 10-100 m

Discussion

Of conservation concern.

Somewhat difficult to locate in the field, Thalictrum texanum is currently known from only two populations. It is closely related to T. arkansanum and T. debile and sometimes treated as a variety of the latter.

Thalictrum confine is quite similar to T. occidentale and T. venulosum; it has been treated as a variety or synonym of the latter (R. S. Mitchell 1988).

Selected References

None.

Lower Taxa

None.
... more about "Thalictrum texanum"
not reflexed +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Marilyn M. Park +  and Dennis Festerling Jr. +
(A. Gray) Small +
cuneate +, truncate +  and cordate +
Thalictrum debile var. texanum +
straight +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
compressed;ovoid +
globose;cylindric +
10-100 m +
not white +  and colored +
1.5 cm15 mm <br />0.015 m <br /> (?) +
pistillate +  and staminate +
showy +  and inconspicuous +
unisexual +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
stipitate +, sessile +  and aggregate +
falcate;ovoid;obovoid +
Margins or openings of mesic woodlands or forests +
compound +  and simple +
whorled +, opposite +  and alternate +
cauline +  and basal +
lobed +, cleft +, cuneate +  and reniform +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
palmate +  and pinnate +
(1-)2-200-flowered +
distinct +
conspicuous +
reduced +
Flowering early spring (Mar–Apr). +
1 +  and 16 +
Fl. S.E. U.S., +
not arillate +  and stalked +
whitish;greenish yellow or purplish +
not persistent +
distinct +
lanceolate +  and obovate +
0.1 cm1 mm <br />0.001 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
ribbed +  and veined +
Conservation concern +  and Endemic +
10 cm100 mm <br />0.1 m <br /> (45 cm450 mm <br />0.45 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
persistent +
glaucous;glabrous +
Thalictrum texanum +
Thalictrum sect. Heterogamia +
species +
not anastomosing-reticulate +
herbaceous +  and woody +