226 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



1. Lysimachia nummularia L. Moneywort. 

 Moist places, chiefly in alluvial soil; well established at several localities. May- 

 June. Naturalized from Eur. in the northeastern U. S. 



2. Lysimachia quadrifolia L. Crosswort. 

 Moist or dry open woods, or low meadows or thickets; common. May-June. 



Eastern N. Amer. 



3. Lysimachia terrestris (L.) B. S. P. 



Low moist or marshy situations; not uncommon, especially along the Potomac. 

 June-July. Eastern N. Amer. (L. stricta Ait.) 



Lysimachia producta (A. Gray) Fernald, a supposed fertile hybrid of the two last 

 pecies, is intermediate in characters. It is known locally from two collections. 



3. STEIRONEMA Raf. Loosestrife. 



Stem leaves narrowly linear, stiff, prominently 1-nerved, the lateral veins obscure. 



1. S. quadriflorum. 

 Stem leaves narrowly lanceolate to ovate or oblong, thin, pinnately veined. 

 Upper leaves with broadly lanceolate to ovate blades; petioles long, copiously long- 



ciliate throughout 2. S. ciliatum. 



Upper leaves with narrowly lanceolate to oblong blades; petioles often not sharply 

 separated from the blades. 

 Basal leaves and lower stem leaves mostly persistent, the blades round to oblong 

 or oval; stem usually simple; petioles ciliate throughout, the hairs extending 

 along the basal part of the blade; pedicels mostly shorter than the leaves. 



3. S. hybridum. 



Basal leaves and lower stem leaves reduced or rarely persistent; stem commonly 



branched; petioles ciliate chiefly at or near the base; pedicels usually longer 



than the leaves 4. S. lanceolatum. 



1. Steironema quadriflorum (Sims) Ilitchc. 



Moist open places; two or three stations on the Potomac Flats near Chain Bridge; 

 apparently rare. June-Aug. Northeastern U. S. (S. longifolium A. Gray.) 



2. Steironema ciliatum (L.) Raf. Fringed loosestrife. 

 Low moist thickets, chiefly along the Potomac; common. June-July. Widely dis- 

 tributed in N. Amer. 



3. Steironema hybridum (Michx.) Raf. 



Around pools; locally common at Great Falls (both sides of the River) and above 

 Sandy Landing, but not found elsewhere. June-July. Eastern U. S., west to Ariz. 

 (S. ciliatum hybridum A. Gray.) 



Closely related to 8. lanceolatum but, on the basis of local specimens, distinct. 



4. Steironema lanceolatum (Walt.) A. Gray. 



Low or marshy situations; half a dozen localities, mostly along the lower Potomac; 

 apparently not uncommon. June-Aug. Eastern U. S. 



4. ANAGALLIS L. Pimpernel. 



1. Anagallis arvensis L. Poor man's weather-glass. 



Pastures and waste places; several scattered localities. July-Sept. N. Amer. 

 generally; naturalized from Eur. 



5. CENTUNCULUS L. 



1. Centunculus minimus L. Chaffweed. 



Moist soil; uncommon; Woodlawn, and region of Hyattsville and Bladensburg. 

 June. Eastern U. S. and westward. 



