KEY TO FAMILIES. 



17 



; leaves 

 perianth 

 with 2 



fruit 2- 



S. Herbaceous or woody plants 

 with branching nerves ; 

 usually 4-5-cleft ; embryo 

 cotyledons ( Monochla niydece ). 

 T. Trees or shrubs; ovary free. 

 Flowers in dioecious catkins; 



valved 



Flowers not in catkins. 

 Leaves toothed, stipulate. 



Flowers appearing after the 

 leaves ; calyx 5-lobed ; fruit a 3- 



seeded berry 



Flowers appearing before the 

 leaves : perianth 4-5-toothed ; 



fruit dry, 1-seeded 



Leaves entire, not stipulate ; flowers 

 unisexual'; fruit a capsule com- 

 posed of 3 1-seeded carpels (partlv) 

 T. Herbs. 



U. Ovary free. 



Fruit of 3 1-seeded carpels, not en- 

 closed in the perianth and pro- 

 truding from the calyx-like 



involucre (partly) 



Fruit 1-celled, l-seeded, usually in- 

 dehiscent, enclosed in the per- 

 sistant perianth. 

 Leaves stipulate. 

 Stipules forming a membranous 

 sheath: flowers mostly bi- 

 sexual ; leaves alternate and 



entire; stamens 5-8 



Stipules free ; leaves opposite, 

 toothed; flowers unisexual: 



stamens 4-5 



Leaves without stipules ; perianth 

 segments 3-5 ; styles 2-3. 

 Segments herbaceous; fruit in- 

 dehiscent 



Segments scarious ; fruit in- 

 dehiscent or circumsciss 

 U. Ovary adherent to calyx: fruit 

 with 1-2 seeds enclosed in the 

 hardened calyx. 

 Leaves pinnate or palmate ; corolla 

 absent ; calyx with 4-8 lobes 



(partly) 



Leaves simply lobed ; flowers uni- 

 sexual : calyx absent, corolla 5- 



toothed (partly) 



S. Plants almost always herbaceous; 



leaves usually with pa,rallel nerves; 



perianth usually of 6 segments in 2 



rows: cotyledon 1 (Monocotyledons), 



V. Perianth of 6 segments, in 2 rows, 



all or the inner ones petaloid. ' 



Salicacejc 49 



rhamnace.e 11 

 X'lmace.e 48 

 euphoebiace^ 46 



euphorbiace.e 46 



polygonace^ 45 

 urticace.e 47 



Chenopodiace-e 45 

 Amarantace.e 44 



'^- 



ROSACEE 17 



Ambrosiace^ 28 



