18 KEY TO THE GENERA OF MANHATTAN PLANTS. 



90. Crataegus. Fruit a small pome (scarlet), but the pericarp or a 

 portion of it, becoming crustaceous, forming 1 to 5, 1-seeded nutlets. 

 Trees. 



91. Rubus. Fruit an aggregation of numerous little drupelets on an 

 oblong receptacle. Calyx 5 parted, persistent. Shrubs. 



92. Fragaria. Fruit formed of the enlarged and pulpy, scarlet re- 

 ceptacle, with the numerous akenes upjn its surface. Calyx 10- 

 cleft, persistent. Herbs. 



93. Potentilla. Akenes several in a head (receptacle pubescent). 

 Calyx 10-cleft, persistent. Herbs. 



94. Geum. Akenes numerous in a head ; long style persistent 

 (hooked at extremity). Herbs. 



95. Agrimonia. Akenes 2, enclosed in the top-shaped " calyx tube," 

 the upper part of which is beset with numerous hooked bristles. 

 Herbs. 



96. Rosa. Akenes or nutlets several, bony and hairy, enclosed by 

 the urn-shaped fleshy receptacle. Calyx lobes 5, more or less per- 

 sistent. Shrubs. 



97. Primus. Drupe with a large more or less 2 edged stone. (Glo- 

 bose or ovoid, scarlet or yellowish, or dark red.) Trees or shrubs. 



Order 41. LEGU MINOS AE. 



Fruit a legume. A single carpel with a parietal placenta. De- 

 hiscence along both sutures, or indehiscent. Sometimes 2-celled by a 

 false partition between the sutures or jointed by transverse partitions 

 between the seeds. Herbs, shrubs, or trees. 



KEY TO OUR GENERA. 



1. Fruit separating into 1-seeded indehiscent joints, 



flat, beset with minute barbed hairs. Herbs •. . Meibomia. 98 



1. Not separating into joints 2 



2. Legume prickly 3 



2. Legume unarmed 4 



3. Prickles hooked, legume slightly dehiscent, oblong, 



few seeded. Herbs Glyeyrrhiza. 99 



3. Prickles straight, legume 4-valved by the separation 



of the sides from the two thickened margins. 



Seeds several, scurfy. Prickly herbs Morongia. 100 



4. Elongated, usually dehiscent, several seeded, not 



inflated 5 



4. Not elongated, indehiscent or tardily dehiscent 15 



5. Large, woody, scarcely dehiscent 6 



5. Smaller, not woody, dehiscent 7 



6. Oblong, seeds orbicular, flattish, large (H to 2 cm). 



surrounded by pulp. Trees Gymnocladus. 101 



