1915] 



BESSEY rilYLOGENETIC TAXONOMY 149 



Family 197. Mimosaceae. The mimosas. Mostly tropical 

 trees, shrubs, and herbs, with alternate mostly compound 

 leaves; flowers actinomorphic ; stamens 10 or more, usually 

 separate ; carpel 1 ; fruit a legume ; seeds mostly without endo- 

 sperm. Acacia, Mimosa. (Species 1483.) (Pf. 3 3 : 70, 99.) 



Family 198. Cassiaceae. The sennas. Mostly tropical 

 trees, shrubs, and herbs, with alternate mostly compound 

 leaves; flowers zygomorphic; stamens 10 or less, usually sepa- 

 rate; carpel 1; fruit a legume; seeds with or without endo- 

 sperm. Cassia, Caesalpinia, Gleditsia, Gymnocladus. (Species 

 1172.) (Pf. 3 3 : 70, 125.) 



Family 199. Fabaceae. The beans. Mostly herbs of tem- 

 perate climates, but with many shrubs and trees ; leaves alter- 

 nate, mostly compound; flowers zygomorphic; stamens 10 or 

 less, usually more or less united; carpel 1; fruit a legume; 

 seeds usually without endosperm. Lupinus, Medicago, Tri- 

 folium, Robinia, Astragalus, Arachis, Vicia, Pisum, Phaseolus. 

 (Species 6948.) (Pf. 3 3 :70, 184.) 



This family constitutes a well-marked side-line in the order 

 Rosales, with zygomorphic, entomophilous flowers. It is not 

 obvious what relation, if any, exists between this form of the 

 flower, and the legume structure of the fruiting carpel. 



Family 200. Saxifragaceae. Saxifrages. Herbs with alter- 

 nate leaves, regular 4 or 5-merous mostly perfect flowers, with 

 8 or 10 stamens, and usually 2 more or less united carpels 

 which are superior; seeds many; endosperm copious. Saxi- 

 fraga, Heuchera, Mitella. (Pf. 3 2a : 41.) 



Family 201. Hydrangeaceae. Hydrangeas. Shrubs and 

 trees with mostly opposite leaves, and regular 4 or 5-merous 

 mostly perfect flowers, with few (8) to many (40) stamens, 

 and 2-5 united carpels, which are more or less overgrown by 

 the axis-cup ; seeds many ; endosperm copious. Philadelphus , 

 Hydrangea. (Pf. 3 2a :41.) 



Family 202. Grossulariaceae. Gooseberries. Shrubs with 

 alternate leaves, regular 4 or 5-merous perfect flowers, usually 

 5 stamens, and 2 to several united carpels which are wholly 



