KEY TO THE FAMILIES. 11 



20. Flowers regular, --_-_-_-_. -21 

 20. Flowers more or less irregular, - - - - -27 Pontedariaceae 



21. Plants with bulbs or corms, ------- 22 



21. Plants with rootstocks, ------ ss Convallariaceae 



Flowers in umbels, with a scarious involucre, _ _ - si Alliaceae 



22. Flowers solitary, or in racemes or panicles, without involucre, 32 Liliaceae 



23. Stamens and pistils united, flowers irregular, - - 4f Orchidaceae 



23. Stamens and pistils separate, ------- 24 



24. Flowers monoecious or dioecious, ____._- 25 



24. Flowers perfect. - - -----__-_27 



25. Flowers arising Jrom spathes; aquatics, - - - - 2ft 



25. Flowers without spathes; twining vines, - - - 37 Tamaceae 



26. Ovary 1-celled, stigmas usually 3, 16 Elodeaceae 



2ft. Ovary 6-9-celled. stigmas 6-9, each 2-parted, 17 Hydrocharitaceae 



27. Perianth pubescent, -------39 Haemodoraceae 



27. Perianth glabrous, ----------28 



28. Some stamens petaloid, ----------29 



28. No stamens petaloid, ----------30 



29. One stamen with a marginal anther, _ _ - - 43 Cannaceae 



29. One stamen with a 1-celled anther, - - 42 Marantaceae 



30. Stamens 3, anther 1, 2-celled, ----- 41 Alpiniaceae 



30. Stamens 3. anthers 3, ----------31 



30. Stamens 6, ---------36 Leucojaceae 



31. Filaments filiform, anthers extrorse, - - - - 38 Iridaceae 



31. Filaments short, anthers with long connectives, - 44 Burmanniaceae 



Dicotyledones. 



1. Corolla wanting (Apetalae) --------2 



1. Corolla present, petals distinct (Polypetalae) 37 



1. Corolla present, petals more or less united (Gamopetalae) - - - 82 



2. Calyx wanting, at least in the staminate flowers, - - - - 3 



2. Calyx present, sometimes colored, at least in the staminate and in the 



perfect flowers, ----------9 



3. Aquatic herbs with monoecious flowers, surrounded by an in- 

 volucre, --------68 Ceratophyllaceae 



3. Terrestrial herbs, ------____4 



3. Shrubs and trees, flowers rarely perfect, --____ 6 



4. Flowers perfect or polygamous, --------5 



4. Flowers monoecious or dioecious, ----- 101 Euphorbiaceae 



5. Stamens 3-8, carpels almost distinct, stigmas 3-4, - 46 Saururaceae 



5. Stamens rarely more than 2, carpels united, stigma brush-like, 47 Piperaceae 



5. Stamen 1. ovary 4-celled, styles united in pairs, - 102 Callitrichaceae 



6. Flowers in aments, -----------7 



6. Flowers not in aments, ----------8 



7. Ovule solitary, fruit a drupe-like nut, 49 Myricaceae 



7. Ovule solitary, fruit a nut enclosed in a bract, - - 51 Corylaceae 

 7. Ovules numerous, fruit a capsule, seeds with coma, - 80 Salicaceae 

 8. Flowers in heads, fruit consisting of capsules united into a globose 



head, ---------85 Altingiaceae 



8. F'.owers not in heads, fruit a samara or a drupe. - - - 141 Oleaceae 



