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Louisiana broomrape

conifer broomrape

Habit Plants simple or few-branched, 7–40(–54) cm, usually stout, base enlarged in robust specimens. Plants simple or few-branched from near base, 10–40 cm, slender, base enlarged.
Roots

inconspicuous to conspicuous (often forming an amorphous mass), slender, usually branched.

conspicuous (usually forming an irregularly globular mass), stout, unbranched.

Leaves

several to numerous, appressed;

blade lanceolate to lanceolate-ovate, 5–10 mm, margins entire, apex acute, surfaces sometimes glandular-pubescent.

numerous, appressed proximally, spreading distally;

blade lanceolate to oblong-ovate or triangular-ovate, 6–20 mm, margins entire, apex acute to acuminate, surfaces usually glabrous.

Inflorescences

spikelike racemes, purple, lavender, or pallid distally, rarely yellow, sometimes branched, glandular-pubescent;

flowers numerous;

bracts ± reflexed, lanceolate, 8–12 mm, apex acute or attenuate, densely glandular-pubescent.

open, cylindric panicles, ochraceous, red-brown, purple or purple streaked, yellow, or cream-white, loosely branched, rarely simple, cinereous glandular-puberulent;

flowers numerous, widely spaced proximally, clustered distally;

bracts reflexed, narrowly lanceolate, 3–6 mm, apex acuminate, moderately glandular-puberulent.

Pedicels

0–15 mm, much shorter than plant axis;

bracteoles 2.

0–2(–6) mm, much shorter than plant axis;

bracteoles 2.

Flowers

calyx purple, lavender, or pallid, weakly bilaterally symmetric, 8–14 mm, deeply divided into 5 lobes, lobes lanceolate-subulate, glandular-pubescent;

corolla 14–20 mm, tube white to pallid or cream, sometimes pinkish or light purplish tinged distally, sometimes with purple veins, constricted above ovary, slightly curved forward, glandular-pubescent;

palatal folds prominent, yellow, pubescent;

lips externally white to pallid or cream, sometimes pinkish or light purplish tinged, internally pink or purple, sometimes white with purple veins, rarely light yellow, abaxial lip spreading, 3–5 mm, lobes oblong-lanceolate, apex obtuse or rounded, adaxial lip erect or slightly reflexed, 4–6 mm, lobes ovate, sometimes deltate, apex rounded or obtuse to bluntly pointed;

filaments glabrous or pilose at base, anthers included or slightly exserted, glabrous or with few woolly hairs along sutures.

calyx yellow, brown, or purple, ± radially symmetric, 5–8 mm, divided into 5 subequal lobes, lobes slightly shorter than to ca. as long as tube, subulate, puberulent;

corolla 13–19 mm, tube white, cream, or light yellow, sometimes reddish brown to purple tinged or with reddish brown or purple veins, strongly constricted above ovary, bent forward, glandular-pubescent;

palatal folds not prominent, pale or light yellow, glabrous;

lips externally white, cream, or light yellow, sometimes reddish or purplish tinged distally or with reddish brown to purple veins, internally reddish brown to purple, sometimes pale with reddish brown or purple veins, abaxial lip spreading, 3–4 mm, lobes narrowly lanceolate, apex rounded, adaxial lip spreading, 3–4 mm, lobes lanceolate, apex rounded, acute, or emarginate;

filaments with ring of hairs at base, anthers included or 1 pair exserted, glabrous or sparsely pubescent.

Capsules

ovoid, 6–13 mm.

ovoid, 6–7 mm.

Seeds

0.3–0.5 mm.

0.3–0.5 mm.

2n

= 48.

= 48.

Orobanche ludoviciana

Orobanche pinorum

Phenology Flowering Apr–Aug. Flowering Jul–Sep.
Habitat Prairies, sand hills, sand dunes, eroded ground, glades, roadsides. Dry coniferous forests, rocky slopes.
Elevation 0–2500 m. (0–8200 ft.) 200–2500 m. (700–8200 ft.)
Distribution
from FNA
CO; ID; IL; KS; MN; MO; MT; ND; NE; NM; OK; SD; TX; WA; WI; WY; AB; BC; MB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; NM; NV; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Orobanche ludoviciana is one of the most widely distributed species of Orobanche in North America. It commonly occurs in wind and water eroded habitats, principally in the Great Plains of North America and contiguous areas.

Throughout most of its range, Orobanche ludoviciana parasitizes Grindelia squarrosa and several species of Artemisia. However, at the southern limits of the range in Texas, it has been reported on Baccharis, Haploësthes, Heterotheca, and Thelesperma (Asteraceae); in Canada, Heterotheca villosa is an important host. The reports on cultivated crops (tomato and tobacco) are the result of misidentifications by P. A. Munz (1930) and should be attributed to O. cooperi and O. riparia.

The binomial Orobanche ludoviciana has often been broadly applied to several taxa in western states, including several taxa treated herein as species.

P. A. Munz (1930) inadvertently used a specimen of Orobanche riparia to describe and illustrate the corollas of O. ludoviciana as having pointed corolla lobes. This led him to include several western taxa that have pointed corolla lobes within O. ludoviciana, including taxa treated here as species: O. cooperi, O. riparia, and O. valida. L. T. Collins et al. (2009) clarified this issue, pointing out that the corolla lobes are in fact rounded.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Orobanche pinorum is unusual in appearance as the stem and inflorescence axis are often markedly darker in color than the flowers.

Orobanche pinorum is chiefly host-specific on Holodiscus discolor (Rosaceae) and is largely sympatric with that species. There are a few occurrences outside the range of H. discolor where it is reported on other species of Holodiscus. Unverified reports on herbarium sheets of parasitism on various conifers exist. Disjunct locations in Nevada and New Mexico are noteworthy, because they suggest that this species may be found in appropriate habitat in the intervening Great Basin territory.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 17, p. 481. FNA vol. 17, p. 475.
Parent taxa Orobanchaceae > Orobanche Orobanchaceae > Orobanche
Sibling taxa
O. arizonica, O. bulbosa, O. californica, O. cooperi, O. corymbosa, O. fasciculata, O. minor, O. multiflora, O. parishii, O. pinorum, O. ramosa, O. riparia, O. robbinsii, O. uniflora, O. valida, O. vallicola
O. arizonica, O. bulbosa, O. californica, O. cooperi, O. corymbosa, O. fasciculata, O. ludoviciana, O. minor, O. multiflora, O. parishii, O. ramosa, O. riparia, O. robbinsii, O. uniflora, O. valida, O. vallicola
Synonyms Aphyllon ludovicianum, Myzorrhiza ludoviciana, O. ludoviciana var. arenosa, O. multiflora var. arenosa Aphyllon pinorum, Myzorrhiza pinorum
Name authority Nuttall: Gen. N. Amer. Pl. 2: 58. (1818) Geyer ex Hooker: Hooker’s J. Bot. Kew Gard. Misc. 3: 297. (1851)
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