PRIMULACEAE PRIMROSE FAMILY 
NARROW-LEAVED LOOSESTRIFE 
Steironema Ianceolatum (Walt.) Gray 
This genus differs from Lysimachia, preceding, in that 
its leaves are not dotted with glands. The staminodia 
described below are the cause of the genus name Stei- 
ronema, coming from two Greek 
words meaning sterile thread. 
The Narrow-leaved Loose- 
strife is found on low grounds and 
in thickets from Maine and North 
Dakota to Florida, Louisiana and 
Arizona. The stem is usually 1-2 
feet high and bears many opposite 
leaves which, however, often 
appear whorled. 
The yellow flowers are pro- 
duced on slender axillary pedun- 
cles from June to August. The 
5 petals are united at the base. 
There are 5 stamens, 1 at the 
base of each petal. Alternating 
with them are 5 slender filaments 
without anthers; these are the 
staminodia. The pistil is simple 
with a 1-celled ovary, 1 style and 
I stigma, and the fruit is a 10-20-seeded capsule. 
The Southern Loosestrife, Steironema intermedium Kearney, is a 
perennial of dry rocky soil from Virginia to southern Illinois, Ala- 
bama and Tennessee. Its 4-angled stem is 8-28 inches high, smooth 
below and downy and glandular above. The leaves are ovate- 
lanceolate, acute at the tip and somewhat heart shaped at the base, 
2-3 inches long and minutely hairy. The flowers are on slender 
petioles in open leafy panicles. The 5 lanceolate sepals are very 
acutely tipped and the 5 segments of the corolla are tipped with{a 
sharp point. The capsule is shorter than the calyx. 
The Yellow or Trailing Loosestrife, Steironema radicans (Hook.) 
Gray, is a rare and unusual species found only in the southern part 
of Illinois, particularly near river courses. The stem is slender and 
reclining, its elongated branches often rooting in the mud. Leaves, 
on very slender stalks, are lanceolate or broader and round at the 
base. The yellow flowers are less than three-quarters of an inch 
across, and petals and sepals are equal. The fruiting calyx is about 
one-quarter inch long. 
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