FLORA OF THE DISTRICT OF COLUMBIA. 213 



Calyx tube prolonged beyond the ovary. 



Seeds furnished with a tuft of silky hairs; flowers pink; lo ™3^ r 



, 7. EPILOBIUM. 



alternate above 



Seeds naked; flowers yellow; leaves alternate. 

 Stamens equal in length; fruit long, cylindric. 

 Plants large (30-150 cm. high), rather stout; leaves minutely toothed; seeds 



horizontal, angled 8. OENOTHERA 



Plants small (10-70 cm. high), slender; leaves lobed; seeds ascending not 



. , 9. RAIMANNIA. 



Stamentuneq^ie^'thValteinate "longer; fruit Aort, ^^l^I^vea 

 linear to oblong, entire or with very small teeth 10. KNEIFFIA. 



1. CTRCAEA L. Enchanter's nightshade. 



1. Circaea latifolia Hill. ,, > 



Woods; common. June-Aug. Eastern U.S. (C. lutetuma of American authors.) 



2. GATJRA L. 



1. Gaura biennis L. 



Dry soil; frequent. Aug.-Oct. Eastern N. Amer. 



3. CHAMAENERION Adans. 



.m»~m««i n \ Qf-n-n Purple pireweed. 



1. Chamaenenon angushfolium (L.) bcop. 



Clearings and newly burned lands; infrequent. Aug. Widely distributed m N. 

 Amer.; also in Eur. and Asia. (Epilobium angustifohum L.) 



4. JUSSIAEA L. 



1. Jussiaea decurrens (Walt.) DC. 

 Wet places along Hunting Creek. Aug.-Sept. Southeastern U. B.. north to Md. 



5. ISNARDIA L. 



, , . , Water purslane. 



1. Isnardia palustns L. . - . 



Ditches and swamps along the Potomac and its larger tributaries; frequent. July 

 Aug widely distributed L H. Amer. and in the Old World. [Ludmgia palustns 



Ell ") 

 A succulent plant with ovate leaves tapering to a slender petiole. It forms a 



characteristic reddish mat in our small streams and swamps. 



6. LUDWIGIA L. 



Plants hirsute; capsules bristly-pubescent; leaves oblong, or the upper lancedate, 

 blunt at both ends, sessile V""\ ', 1 " tQ J 



Plants glabrous; capsules glabrous; leaves lanceolate or Imear-lance ojate, acute a 

 pointed at both ends, short-petioled 2 - L - auernuoua. 



1. Ludwigia hirteUa Raf. 



Holmead Swamp; not collected recently. July-Aug. N. J. to lex. 



_ Seed-box. 



2. Ludwigia alternifolia L. 



Low woods and swamps; common. June-Aug. Eastern U. b. 



7. EPILOBITJM L. Willow-herb. 



1. Epilobium coloratum Muhl. 

 Low ground; frequent. Aug. Eastern U. S. 



