PRIMULACEAE 



PRIMROSE FAMILY 



NARROW-LEAVED LOOSESTRIFE 



Steironcma lanccolatum (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 i-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, i 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 i-celled ovary, i style and 

 I stigma, and the fruit is a io-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 otten 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 ot an inch 

 across, and petals and sepals are equal. The fruiting calyx is about 

 one-quarter inch long. 



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