131 



A SYNOPSIS OF THE NATURAL SYSTEM; 



A KEY TO TPIE CLASSES AND ORDERS, FOR THE READY ANAL- 

 YSIS OF ANY PLANT EMBRACED IN THIS FLORA. 



§ 1. Classes aud Subclasses. 



1 Flowering plants, or Ph^nogamia. ... 2 



I Flowerless plants, or Cryptogamia. ... 5 



2 Leaves net-veined. Flowers never completely 3-parted. Exogens. ... 3 

 2 Leaves parallel- (rarely net-) veined. Flowers 3-parted. E^vdogen-s. ... 4 



3 Stigmas present. 'Sds. endos.d in seLd-vessels. ... 6. ANGIOSPERMS. I. 



3 SticO. Sds.nak. (Piiie,Fir,&.c.) Coxifer^.CXXXI.GYMNOSPEKMS. II. 

 -4 Fls. with no glumes. PeriantU wliorledor wanting:. . . . 127. AGLUMACE.E. III. 

 4 Fls. with green giumes, no perianth and 1-seededfr. . . . 147. GLUMACEtE. IV. 



5 Stems and lijaves distinguishable. . . . 149. ACROGENS. V. 



5 Stems and leaves confounded together. . . . 151. - -THALLOGENS. VI. 



6 Corolla with distinct petals. ... 7 ----- - Polypetalous Exogeiis. 1 



6 Corolla with united petals. ... 69 - - - - - Monopetalous Exogeus. 3 



6 Corolla (and often the calyx also) wanting. ... 97 - - Apetalous Exogeiis. 3 



§ 2. Orders of tlie Polj^petalous Exogens. 



7 Herbs (§164) 8 



7 Shrubs, trees or under-shrubs. ... 48 

 8 Leaves alternate or all radical. ... 9 

 8 Leaves cauline, opposite, at least the lower ones. ... 35 



9 Leaves furnished with stipules. ... 32 



9 Leaves destitute of stipules. ... 10 

 10 Polyandrous — stamens 17 — 200, indefinite. ... 11 

 10 Oligandrous — stamens few and definite. ... 16 



II Stamens hypugynous — situated on the receptacle. ... 12 



11 Stamens perigynous — situated on the calyx or corolla. ... 15 

 12 Sepals 3 — 5. Leaves centrally peltate, in water. ... 13 

 12 Sepals 3—9. Leaves neither peltate nor tubular. ... 14 



12 Sepals 5, persistent. Leaves tubular, pitcher-for.ai. - - Sarraceniaceb. X. 

 12 Sepals 2, deciduous. Juice usually colored. - - - - Papaverace*. XL 



13 Petals 3 or 4, in one row. Lvs. oval, floating. - - Cabombace*. VII. 



13 Petals many, in several rows. Lvs. round, erect. - Nelumbiace.e. VIII. 

 14 Pistils (or pistil) simple and distinct, fevv^ or many. - - - Ranu.vculacejE. I. 

 14 Pistil compound, large 12— 30-celled. (In water.) - - - Nymph^aceji:. IX. 



15 Petals 5. Styles several, distinct. Ro3ace.e. XLVIII. 



15 Petals 5. Styles united into one. Loasaces. LVI. 



15 Petals numerous, in several rows. Styles united. - - Cactace^. LXI. 

 16 Flowers very irregular, one-sided or two-sided. ... 17 

 16 Flower regular or nearly so. . . . 19 



17 Filaments 6 — 8, united below into 2 sets. ... 18 



17 Filaments 5, united only at top. ----- Balsaminace^. XXVIII. 



17 Filaments 8, distinct. Leaves simple, peltate. - TROP.EOLACEa:. XXIX. 



17 Filaments 8, distinct. Lvs. biternate, with tendrils. Sapindace.e. XLIV. 

 18 Leaves much dissected and divided. ------- Fumari.^ce.e. XII. 



18 Leaves simple, entire. - Polygalace«. XVI. 



19 Ovary superior — free from the calyx or nearly so. . . . 20 



19 Ovary inferior — wholly adherent to the calyx. ... 30 



20 Sepals 2. Fleshy herbs. Portulacace^. XXIV. 



20 Sepals 3 or more. Herbs leafy, green. ... 21 



20 Sepals 3 or more. Herbs leafless and not green. ... 87 - - - (LXXVIII.) 



21 Stamens hypogynous — situated on the receptacle. ... 22 



21 Stamens perigynous — situated on the calyx or corolla. ... 28 

 22 Sepals, petals and stamens symmetrical. ... 23 

 22 Sepals, petals and stamens unsymmetrical. Fruit a pod. ... 26 



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