BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Hedysarum alpinum var. americanum | American Sweetvetch 



GENERAL BOTANICAL CHARACTERISTICS : 
American sweetvetch is a native, perennial forb with a woody taproot.
It grows in tufts, 8 to 30 inches (20-75 cm) high, with long, erect
stems.  The perfect flowers are papilionaceous and vary from pink to
purple.  The fruit is a flat loment, constricted into more or less oval,
indehiscent segments with four to six seeds [1,10,15,20].


RAUNKIAER LIFE FORM : 
   Chamaephyte


REGENERATION PROCESSES : 
American sweetvetch reproduces sexually.  The flowers are pollinated by
honey bees.  The erect stems aid in natural seed dispersal by gravity
and wind.  Field seed has shown a germination rate of 97 to 100 percent.
Scarification increases germination rate [1].  Plants grow in groups of
a few to hundreds of individuals [1,11].


SITE CHARACTERISTICS : 
American sweetvetch grows in meadows and on slopes from low to fairly
high elevations [15].  It occurs on shale slides, roadside verges, and
forest fringes [1,20], and often occurs near water, such as on sand
bars, point bars, limey rivershores, lakeshores, and near seashores
between beach and forest [4,17,20,21].  It can grow on shallow, poorly
developed, rocky, dry, calcareous soils or in cold, wet, acidic, organic
substrates [4,7,16,17].  It does not do well in poorly drained, bog-type
woodlands [17].  American sweetvetch may occur in wetlands, although it
usually does not [19].  It survives in areas that occasionally flood
[17].

American sweetvetch is found at the following elevations [5,6,7,13].

        1,720 to 2,480 feet (525-757 m) in AK
        3,770 to 4,260 feet (1150-1300 m) in AB
        5,000 feet (1525 m) in MT
        8,100 to 8,200 feet (2470-2500 m) in WY


SUCCESSIONAL STATUS : 
NO-ENTRY


SEASONAL DEVELOPMENT : 
American sweetvetch begins to grow in May, earlier than other perennial
legumes.  It produces buds in June and flowers in June and July [1].
The seeds ripen in July and August; the pods ripen unevenly.  The
seedlings and mature plants are moderately tolerant to spring and fall
frosts, suffering some winterkill [1].

Related categories for Species: Hedysarum alpinum var. americanum | American Sweetvetch