FLORA OF THE DISTRICT OF COLUMBIA. 151 



1. ANYCHIA Michx. Forked chiceweed. 



Plants finely hairy, rather stout, the stems with short joints, usually low and spreading; 

 flowers nearly sessile 1. A. polygonoides. 



Plants glabrous, very slender, the stems with long joints, erect; flowers on conspicu- 

 ous pedicels 2. A. canadensis. 



1. Anychia polygonoides Raf. 



Dry hillsides; frequent. July-Sept. Eastern U. S. (A. dichotoma of some 

 authors, not of Michaux.) 



2. Anychia canadensis (L.) B. S. P. 



Dry woods; frequent. July-Sept. Eastern U. S. (.4. dichotoma capillacea Torr.) 



2. PARONYCHIA Adans. 



1. Paronychia dichotoma (L.) Nutt. Whitlow-wort. 



On rocks at Little Falls and Great Falls. July-Oct. Md. to Tex. 



3. SCLERANTHUS L. 

 1. Scleranthus annuus L. Knawel. 



Easbys Point, north of Old Observatory; Ammendale. May. Native of Eur.; 

 frequently adventive in N. Amer. 



53. ALSINACEAE. Chickweed Family. 



Plants with scarious stipules; leaves sometimes whorled, linear; petals sometimes 

 pink. 



Leaves opposite; petals pink; styles 3 1. TISSA. 



Leaves whorled; petals white; styles 5 2. SPERGULA. 



Plants without stipules; leaves never whorled; petals white or wanting. 



Capsule usually twice as long as the calyx or longer, cylindric, slightly curved, 

 opening at the apex by 10 minute teeth; plants usually with viscid pubescence. 



Petals deeply cleft, or rarely wanting 3. CERASTIUM. 



Capsule less than twice as long as the calyx, ovoid or oblong, not curved, opening 

 by 6 or fewer valves; plants without viscid pubescence. 



Petals deeply 2-cleft 4. ALSINE. 



Petals entire, or sometimes wanting. 



Leaves ovate; sepals acute; styles fewer than the sepals 5. ARENARIA. 



Leaves narrowly linear; sepals obtuse; styles as many as the sepals. 



6. S AGIN A. 



1. TISSA Adans. 



1. Tissa rubra (L.) Britton. Sand spurry. 



Occasional in waste ground and along roadsides. Apr.-Tiily. Widely distributed 



in the U. S.; perhaps native in some parts of N. Amor., but largely adventive from 



Eur. and Asia. (Spergularia rubra Presl; Lepigonuin rubrum Fries.) 



2. SPERGULA L. 



1. Spergula arvensis L. Spurry. 



Waste ground; Washington and Ammendale. June- July. Native^of Eur.; widely 

 naturali^'.ed ia N. Amer. 



Oii3 ci our s;)e -im^n^! is a very viscid plant Avith conspicuoxisly margined seeds, 

 suggesting 5. salioa Boena. The seeds, however, are papillose, as in ^S. arvensis. 

 The differences between the two species do not seem very constant. 



3. CERASTIUM L. 



Petals more than twice as long as the sepals. Plants perennial; pedicels usually 

 lower than the calvx: caosule about twice as long as the sepals. .1. C. velutinum. 



