USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

Physostegia Benth. -- Obedient plant


Stout, erect, perennial herbs; stems arising singly from slender rhizomes or from a slender caudex, simple throughout or branched at the base of the inflorescence. Leaves sessile or the lowermost sometimes short-petioled, elliptic to lanceolate or oblanceolate, mostly serrate. Flowers showy, pinkish-lavender to purple-lavender, short-pedicelled and borne singly in the axils of short bracts, arranged in 1-several terminal and lateral, spikelike racemes. Calyx regular or nearly so, tubular-campanulate, 5-toothed, the teeth much shorter than the tube; corolla bilabiate, much longer than the calyx, the upper lip hoodlike, entire to emarginate, the lower lip about equaling or shorter than the upper, shallowly 3-lobed; stamens 4, included or slightly exserted under the upper corolla lip; stigma 2-lobed, style about equaling the stamens. Nutlets ovoid, unequally trigonous, smooth.

References:  

Cantino, P. D.  1981.  Change of status for Physostegia virginiana 
     var. ledinghamii (Labiatae) and evidence for a hybrid 
     origin.  Rhodora 	83:111-118. 

Lundell, C. L.  1959.  Studies in Physostegia I.  New species and 	
     observations on others.  Wrightia 2:4-12.

Lead Characteristic Go To
1 Upper leaves clasping the stem, some of them usually broadest near the base of the blade; corolla usually with some stipitate glands (often lacking in P. ledinghamii); rare species in our area. Lead 2
1 Upper leaves not clasping the stem, broadest at the middle or above; corolla glabrous or sparsely puberulent but lacking stipitate glands; common species. P. virginiana
2 Corolla 14-23 mm long, often lacking stipitate glands; nutlets 2.8-4 mm long. P. ledinghamii
2 Corolla 9-16 mm long, usually with stipitate glands; nutlets 2.1-3.3 mm long. P. parviflora


41. Lamiaceae, the Mint Family
3. Physostegia Benth. -- Obedient plant
1. Physostegia ledinghammii (Boivin) Cantino
2. Physostegia parviflora Nutt. ex A. Gray
3. Physostegia virginiana (L.) Benth.


Return to Family -- Lamiaceae - The Mint Family
Return to Contents

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/plants/vascplnt/genphyso.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:38:40 EST
Reston, VA [vaww54]