Orobanche uniflora

Linnaeus

Sp. Pl. 2: 633. 1753.

Common names: One-flowered or small cancer-root one-flowered or naked broomrape orobanche uniflore
Synonyms: Anoplanthus uniflorus (Linnaeus) Endlicher Aphyllon uniflorum (Linnaeus) Torrey & A. Gray Thalesia uniflora (Linnaeus) Britton
Treatment appears in FNA Volume 17. Treatment on page 472. Mentioned on page 467, 469, 473, 474.

Plants simple or few-branched basally, sometimes forked medially, 3.5–18 (–25) cm (including pedicels), stem portion 1–5 (–7) cm, slender, base not enlarged. Roots inconspicuous, slender or stout, unbranched or few-branched. Leaves relatively few, loosely imbricate or more remote, loosely ascending to spreading; blade oblong-lanceolate to awl-shaped, 2–10 mm, margins entire, often inrolled, apex acuminate, surfaces glabrous. Inflorescences of solitary flowers or fascicles of 2 (–4) at stem or branch tips, white to cream, sometimes purple-tinged, simple, glabrous; bracts loosely ascending and erect, oblanceolate to broadly ovate, obovate, rhombic, or awl-shaped, 5–12 mm, apex acute to acuminate, glabrous, rarely glandular-pubescent distally. Pedicels (8–) 20–110 (–170) mm, much longer than plant axis; bracteoles 0. Flowers: calyx white to straw colored or light yellow, or pale to dark, dull purple, sometimes brownish, ± radially symmetric, 4–12 (–15) mm, divided into 5 subequal lobes, lobes slightly shorter than to 2 times as long as tube, ± triangular or subulate-triangular, sparsely to moderately glandular-pubescent; corolla (11–) 15–30 (–35) mm, tube white to purple, blue, or yellow, sometimes lighter proximally or with light or darker purple or blue veins, slightly to moderately constricted above ovary, ± bent forward, glandular-pubescent; palatal folds ± prominent, bright-yellow, glandular and/or eglandular-pubescent, sometimes glabrescent; lips white, yellow, purple, or blue, sometimes with light or darker purple or blue veins, abaxial lip slightly to moderately spreading, sometimes ± recurved distally, (1–) 2–6 (–9) mm, lobes oblong-obovate to nearly round, apex rounded to bluntly pointed or shallowly emarginate (sometimes with 2 notches), adaxial lip slightly to moderately spreading, sometimes recurved, 2–6 (–9) mm, lobes broadly oblong-ovate to oblong-semiorbiculate, apex rounded, rarely bluntly pointed or shallowly emarginate; filaments glabrous, anthers included, glabrous or villous-tomentose. Capsules ovoid to oblong-ovoid, 4–8 (–11) mm. Seeds 0.1–0.4 mm.

Distribution

Alta., B.C., Man., N.B., N.S., Nfld. and Labr. (Nfld.), Ont., P.E.I., Que., Sask., Alaska, Ariz., Ark., Calif., Colo., Conn., D.C., Del., Fla., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Mass., Md., Mich., Minn., Miss., Mo., Mont., N.C., N.Dak., N.H., N.J., N.Mex., N.Y., Nebr., Nev., Ohio, Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., Wyo., Mexico

Discussion

Subspecies 2 (2 in the flora).

Orobanche uniflora forms a polymorphic complex that requires more detailed study. The detection of broad-scale patterns of morphological variation is confounded by the differentiation among local races. D. M. Achey (1933) recognized five varieties, and K. C. Watson (1975), in her unpublished thesis, revised the classification to three subspecies. The present treatment, which accepts only the two major infraspecific variants as subspecies, should be considered highly tentative.

Selected References

None.

Key

1 Calyx lobes slightly shorter than to only slightly longer than tubes, narrowly to broadly lanceolate-triangular; corollas white to pale yellow, sometimes pale purplish tinged and/or with light purple veins. Orobanche uniflora subsp. uniflora
1 Calyx lobes ca. 2 times as long as tubes, subulate-triangular; corollas purple to blue (often with a white throat), yellow, or white, often with darker purple or blue veins. Orobanche uniflora subsp. occidentalis
... more about "Orobanche uniflora"
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
recurved +  and spreading +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
recurved +  and spreading +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
villous-tomentose +  and glabrous +
glandular-pubescent +  and glabrous +
emarginate +, pointed +, rounded +  and bluntly pointed or shallowly emarginate +
L. Turner Collins +, Alison E. L. Colwell +  and George Yatskievych +
Linnaeus +
not enlarged +
oblong-lanceolate;awl-shaped +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not leathery +, not +  and fleshy +
erect +  and ascending +
oblanceolate +  and broadly ovate obovate rhombic or awl-shaped +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
brownish +, white +  and straw colored or light yellow or pale +
divided +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
ovoid;oblong-ovoid +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
One-flowered or small cancer-root +, one-flowered or naked broomrape +  and orobanche uniflore +
3 cm30 mm <br />0.03 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
pallid +, tinged pink +  and purple yellow or blue +
bent +  and tubular +
constricted +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
spikelike +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, Nfld. and Labr. (Nfld.) +, Ont. +, P.E.I. +, Que. +, Sask. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, D.C. +, Del. +, Fla. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Maine +, Mass. +, Md. +, Mich. +, Minn. +, Miss. +, Mo. +, Mont. +, N.C. +, N.Dak. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, Nebr. +, Nev. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Utah +, Va. +, Vt. +, W.Va. +, Wash. +, Wis. +, Wyo. +  and Mexico +
2 +  and 1 +
bright-yellow +
glabrescent +, eglandular-pubescent +  and glandular +
indehiscent +, septicidal +, loculicidal +  and dehiscence +
purple-tinged;white;cream +
axillary +  and terminal +
deciduous +
loosely ascending +  and spreading +
blue +, purple +, yellow +  and white +
loosely ascending +  and recurved +
glandular-pubescent +
broadly oblong-ovate +  and oblong-semiorbiculate +
subequal +
erosulate +, erose +  and entire +
lobed +, toothed +  and entire +
tenuinucellate +  and unitegmic +
campylotropous-like +
spikelike +
11 cm110 mm <br />0.11 m <br /> (17 cm170 mm <br />0.17 m <br />) +
2 cm20 mm <br />0.02 m <br /> (11 cm110 mm <br />0.11 m <br />) +
spikelike +
few-branched +  and unbranched +
inconspicuous +
coralloid +
stout +  and slender +
black;tan;dark-brown +
500 +  and 2000 +
prismatic +, ovoid +  and oblong-ellipsoid +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
5 +  and 4 +
subequal +
yellow +  and white +
aerial +  and subterranean +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
puberulent +  and glabrous +
capitate +  and crateriform-peltate +
clavate +  and 2-4-lobed +
Anoplanthus uniflorus +, Aphyllon uniflorum +  and Thalesia uniflora +
Orobanche uniflora +
Orobanche +
species +
blue;darker purple;light;lighter;white;purple blue or yellow +
glandular-pubescent +
constricted +
blue +, darker purple +  and light +
few-branched +  and simple +
18 cm180 mm <br />0.18 m <br /> (25 cm250 mm <br />0.25 m <br />) +
perennial +  and annual +
holoparasitic +  and hemiparasitic +