FLORA OF THE DISTRICT OF COLUMBIA. 177 



3, Agrimonia parviflora Ait. 



Sandy fields; frequent. July-Aug. Northern states, south to Ga. 



4. Agrimonia pubescens Wallr. 



Opeu woods; frequent, July. Northern states, south to (la. (A. mollis Britton.) 



12. APHANES L. 



1. Aphanes arvensis L. Lady's-maxtle. 



Old fields and waste places; rare. June. Introduced from Eur. (Alehemilla 



arvensis Scop.) 



13. SANGUISORBA L. 



1. Sanguisorba canadensis L. American SUBNET. 



Bogs and swales; infrequent. Aug. Northern states, south to Ga. (Poterium cana- 



dense A. Gray.) 



14. POTERIUM L. 



1. Poterium sanguisorba L. Salad subnet. 



Fields and waste places; infrequent. May. Northern states, south to Md. 

 (Sanguisorba minor Scop.) 



80. MALACEAE. Apple Family. 



Cotoneaster pyracantha (L.) Spach, native of Europe and Asia, was reported by Steele 

 as an escape from cultivation. 



Plants usually armed with spines; mature carpels (" seeds ") hard and bony. Flowera 

 in corymbs 5 - CRATAEGUS. 



Plants without spines; mature carpels ("seeds") papery or leathery. 

 Flowers in racemes; cells of the mature fruit twice as many as the styles. 



4. AMELANCHIER. 



Flowers in corymbs or cymes; cells of the mature fruit as many as the styles. 



Plants shrubs; cymes compound, branched 3- ARONIA. 



Plants trees; cymes simple. 

 Flesh of the fruit with grit cells; opening of the receptacle partly closed by a 



disklike cushion; flowers white !■ PYRUS. 



Flesh of the fruit without grit cells; opening of the receptacle open; flowera 

 usually pink or tinged with pink 2. MALUS. 



1. PYRUS L. 



1. Pyrus communis L. Pear. 



Occasional in woods and waste ground . Apr. Native of Eur! ; cultivated and often 



escaping. 



2. MALUS Mill. 



Leaves and outer surface of calyx lobes glabrous 1. M. coronaria. 



Leaves and outer-surface of calyx lobes white-woolly 2. M . sylvestris. 



1. Malus coronaria (L.) Mill. American crab apple. 

 Thickets along the Northwest Branch west of Hyattsville; rare. Apr.-May 



Eastern U. S. (Pyrus coronaria L.) 



2. Malus sylvestris Mill. Apple. 

 Occasional in woods and waste ground. Apr.-May. Native of Asia; cultivated 



and escaping. (Pyrus malus L; M. malus Britton.) 



The cultivated crab apples are derived from the Siberian crab apple, Malus baccata 

 (L.) Borck., or from hybrids between this and the common apple. The Soulard crab 

 apple is a hybrid between Malus sylvestris and one of our native species. 

 69289—19 12 



