BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Polygonum spp. | Smartweed 



GENERAL BOTANICAL CHARACTERISTICS : 
Smartweed is a highly variable genus, which includes annual or perennial
forbs and shrubs [15].  Some species are viney.  The leaves are usually
simple and alternate.  The pink, green, or white flowers have jointed
stalks and stems have swollen nodes [17].  Flowers can be either perfect
or imperfect.  The fruit is a three- or four-angled achene [20].  Some
species have rhizomes or taproots [35].


RAUNKIAER LIFE FORM : 
   Chamaephyte
   Cryptophyte: Geophyte


REGENERATION PROCESSES : 
Smartweed reproduces by seed and by rhizomes.  The average number of
seeds for P. hydropiperoides collected on the Texas Gulf Coast was 581
pounds per acre (650 kg/ha) dry weight [32].


SITE CHARACTERISTICS : 
Smartweed species are mostly found in wetlands, sandy beaches, saline or
brackish ponds and marshes, and in inundated swales and marshes [15].
They can also be found in cultivated fields, thickets, swampy woods,
clearings, wastelands, along roadsides, in prairies, and on rocky, dry
or cool and damp slopes.  Some species grow in alpine or subalpine
meadows and on rocky summits [15].  P. careyi is reported to occur on
recent burns.  Elevational ranges for some western species of smartweed
have been listed as follows [12]:

Utah:     from 4,200 to 12,300 feet (1,280-3,750 m)
Colorado: from 3,500 to 13,400 feet (1,067-4,085 m)
Wyoming:  from 3,500 to 12,000 feet (1,067-3,660 m)
Montana:  from 2,800 to 10,500 feet (853-3,200 m)


SUCCESSIONAL STATUS : 
Many smartweed species are introduced, while others are native to North
America.  Most are shade intolerant [15].  P. cilinode appears to be
dominant on severely burned forested areas of northern Minnesota for the
first three postfire seasons [1].  Some species of smartweeed are
dominant in the nonpersistent emergent marsh communities of the Savannah
River in South Carolina [27].  P. coccineum is an indicator of fire in
wetlands [28].  Other species of smartweed are early seral species which
dominate sites for the first 5 to 7 postdisturbance years [2].


SEASONAL DEVELOPMENT : 
Flowering dates for smartweed species vary.  Most of the southern
species flower in May and June, while their northern counterparts flower
from July through November.  Some species in Texas, Arkansas, and
Oklahoma can flower as late as November [15].

Related categories for Species: Polygonum spp. | Smartweed