PRIMROSE FAMILY PRIMULACEAE 
MARSH LOOSESTRIFE 
Steironema quadriflorum (Sims) Hitchc. 
This showy perennial herb grows along streams and lakes 
and in swamp borders from Virginia to western New York, 
west to Missouri and Manitoba. It is common in such places in 
Illinois, especially in the north. 
The smooth 4-sided stem grows 
6-36 inches high and branches little 
or not at all. All but the lowest 
leaves are sessile and similar to those 
shown. They are very narrow, I- 
nerved and with slightly rolled mar- 
gins, opposite but often with clusters 
of smaller leaves in their axils. The 
basal leaves are broader and shorter 
on slender petioles. 
The yellow flowers appear in 
June and July, tending to be pro- 
duced in fours at the ends of the 
branches. The persistent calyx is 
s-lobed and somewhat shorter than 
the corolla. The deeply 5-parted and 
wheeled-shaped corolla is yellow and 
beautifully fringed; to it are at- 
tached the perfect stamens, 1 at the 
base of each petal, and the 5 sterile 
filaments or staminodia which alter- 
nate with the petals. The pistil has 
a nearly spherical ovary and a 
slender style. The fruit is a capsule 
containing somewhat angled seeds. 
The Common or Fringed Loosestrife, Steironema ciliatum (L.) 
Raf., is the largest of the genus, growing 1-4 feet high. It is also 
distinguished by its broad leaves, heart shaped at the base. The 
margins of the leaf base and the petioles are fringed with long white 
hairs. The large yellow flowers, blooming from June through 
August, have their corollas longer than the calyx, and the latter is 
also exceeded in fruit by the capsule. This species may be found in 
low grounds and thickets from Nova Scotia to British Columbia, 
south to Georgia and Arizona. 
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