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Swamp Lousewort

Pedicularis lanceolata




Swamp Lousewort
 Pedicularis lanceolata



State Heritate Status Rankings

Arkansas (S1), Connecticut (S1S2), Delaware (SH), Georgia (S1), Illinois (SNR), Indiana (SNR), Iowa (S4),
Kentucky (SH), Maryland (S1), Massachusetts (S1), Michigan (SNR), Minnesota (SNR), Missouri (SNR), Nebraska (S2),
New Jersey (S3), New York (S2), North Carolina (S1), North Dakota (SNR), Ohio (SNR), Pennsylvania (S1S2),
South Dakota (SNR), Tennessee (S1S2), Virginia (S3), West Virginia (S2), Wisconsin (SNR)



 

Description:

Swamp lousewort is an erect, simple or few branched (NPWRC 2003) herbaceous perennial herb with hollow 4-angled stems (Missouri Flora 2003) growing to approximately 4 to 8 dm in height (Radford et. al. 1968). The stems are predominantly glabrous, green and with purple vertical stripes in the internodes. The internodes have vertical lines of curled hairs in the internodes visible with a hand lens. The opposite leaves have short petioles approximately 1 cm in length (Missouri Flora 2003) or are sessile or subsessile (NPWRC, 2003) and are predominantly glabrous except for scattered hairs on the margins (Missouri Flora 2003). The elliptic-lanceolate (Radford et. al. 1968) linear-oblong to oblong-lanceolate leaves (Missouri Flora 2003) are shallowly crenately lobed and grow to approximately 5 to 8 cm in length by 1 to 2 cm in width (Radford et. al. 1968) exhibiting a deep green coloration and lighter on the undersurface. Leaves are sparsely pubescent on both surfaces (Missouri Flora 2003).

Swamp lousewort produces both a terminal inflorescence and flowers on bracteate spikes up to approximately 10 cm in length during the months from August through October. Each flower is subtended by a foliaceous bract with a distinctly bent petiole and a pair of basal auricles which spread laterally. The corolla is white and approximately 2.5 cm in length, strongly compressed, bilabiate, zygomorphic, and glabrous externally. The single-lobed upper lip is galeate and approximately 1 cm in length. The lower lip is also approximately 1 cm in length, but 3-lobed at the apex with 2 central folds lading into the throat of the corolla. The lobes of the lower lip are rounded and 3 to 4 mm in length by 2 to 3 mm in width. The stamens are 4 in number included in the galea of the upper lip. The filaments are translucent white, predominantly glabrous, but with a few hairs at the base, compressed, thin, and 2 to 2.5 cm in length. The anthers are 3 to 4 mm in length and yellowish-brown in coloration. The stigma is green in coloration and minute. The ovary is conical in shape, green, slightly compressed, glabrous with a swollen nectariferous base, 2-ocular, and 3 mm in length during flowering. The calyx is green, 2-lobed and 1.4 cm in length when in flower. The calyx lobes have orbicular appendages at the apex (Missouri Flora 2003). The fruit (capsule) is obliquely ovid and mostly included in the calyx.

Habitat:

Swamp lousewort inhabits wet meadows on basic soils (Radford et. al. 1968), fens, and springs (NPWRC 2003).

Range:

Swamp lousewort is found in the northern and eastern United States.





References

  • NatureServe. 2003. Internet Resource. NatureServe.

  • Radford, A.E., Ahles, H.E., Bell, C.R. 1968. Manual of the Vascular Flora of the Carolinas. The University of North Carolina Press, Chapel Hill, North Carolina.

  • The Missouri Flora Website. 2003. Swamp Lousewort Species Description. Internet Resource: Missouri Flora Website (Accessed December 13, 2003).

  • USDA, NRCS. 2002. The PLANTS Database, Version 3.5. Internet Resource USDA Plants Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • US Geological Survey (USGS). 2003. Swamp Lousewort Species Description. Aquatic and Wetland Vascular Plants of the Northern Great Plains 45. Scrophulariaceae, the Figwort Family. Internet Resource: Swamp Lousewort Species Description (Accessed December 13, 2003).

  • Weakley, A.S. July 2002. Flora of the Carolinas and Virginia, Working Draft. Internet Resource. Flora of the Carolinas and Virginia.