Plant

Polygonum lapathifolium L.

 

=Persicaria lapathifolia

 

Polygonaceae (Buckwheat Family)

 

Native

 

Willow Smartweed  

 

Pale Smartweed 

                               June Photo

 

Plant Characteristics:  Erect or ascending annual, the stems simple or branched, usually swollen at nodes and 5-15 dm. high; lvs. lanceolate, glabrous, narrowed at base, to 20 cm. long, 5 cm. wide, attenuate at apex, margin and midrib with fine upwardly appressed hairs; ocreae cylindric, veined; peduncles often with subsessile glands; spikes slender, cylindric, 1-6 cm. long, often nodding; perianth greenish to pink or purplish, ca. 2 mm. long; calyx white or pale pink, 5-parted; stamens 6; sheathing bracts membraneous, glabrous, with long tapering point and green keel on back, greenish at base and dk. pink in upper half; achene lenticular with concave faces, ovate, +/- 2mm. broad, dark brown and finely punctate.

 

Habitat:  Common in moist places below 5000 ft.; several Plant Communities; throughout temperate N. Am.  June-Oct.

 

Name:  See P. aviculare for meaning of genus name.  Latin, lapathium, sorrel and folium, leaf.  (Jaeger 104,136).  Sorrel-leaved. 

 

General:  Occasional in the study area.  Found along fresh water areas and in 2002 several widely spread plants were found in the 23rd St. creek growing in 6-8 inches of water.  Photographed in the Delhi Ditch, along Back Bay Dr. at the north end of Eastbluff and on the Castaway's Beach.  (my comments).     Indians used Polygonum species seeds for food and the roots for medicine.  (Heizer and Elsasser 249).      Polygonum species have been known to accumulate free nitrates in quantities capable of causing death or distress in cattle.  (Fuller 386).      The Yokut Indians of central California used P. lapathifolium as a fish poison.  (Campbell 433).       Highly variable, some forms are induced by environment. Merits study.  (Hickman, Ed. 890).  The genus Persicaria is not mentioned in the 1993 Jepson manual.  (my comment).

 

Text Ref:  Hickman, Ed. 890; Munz, Flora So. Calif. 704; Robbins et al. 137; Roberts 34.

Photo Ref:  June 1 83 # 11; June 6 83 # 25,26; May 3 84 # 13,17; Oct 1 84 # 15.

Identity: by F. Roberts.

First Found: June 1983.

 

Computer Ref:  Plant Data 258.

Have plant specimen.

Last edit 10/15/04.  

                                   May Photo                                                                                 June Photo