350 NATURAL SYSTEM OF LINDLET. 



SEXUAL OR FLOWERING PLANTS. 



Fructification springing from a thallus,.. in. Khizogens. 



Fructification springing from a stem, 

 Wood of stem youngest in the centre, cotyledon single. 

 Leaves parallel-veined, permanent, wood of stem al- 

 ways confused, IV. Endogens. 



Leaves net-veined, deciduous, wood of stem, when 



perennial, arranged in a circle with a central pith, V. Dictyogens. 

 Wood of stem youngest at the circumference, always 

 concentric, cotyledons two or more. 



Seeds quite naked, VI. Gymnogens. 



Seeds enclosed in seed-vessels, VII. Exogens. 



The following are the subclasses of Endogens and Exogens adopted by 

 Lindley: 



ENDOGENS. 



Subclass I . Glumaceous. Floral envelopes imbricated. 

 2. Petaloid Floral envelopes verticillate. 



a. Unisexual, often achlamydeous. 



6. Hermaphrodite, ovary adherent. 



c. Hermaphrodite, ovary free. 



EXOGENS. 



Subclass 1. Diclinous. Flowers unisexual. 



2. Hypogynous. Flowers usually hermaphrodite, stamens completely 



hypogynons, free from the calyx or corolla. 

 3. Perigynous. Flowers usually hermaphrodite, stamens growing to the 



side of either the calyx or corolla; ovary superior, or nearly so. 

 4. Epigynous Flowers usually hermaphrodite, stamens growing to 



the side of either the calyx or corolla ; ovary inferior, or nearly so- 



Under the classes, Lindley enumerates 303 natural orders, which are 

 grouped together under 56 alliances. In this system of Lindley, the 

 divisions of Asexual and Sexual plants correspond to Endlicher's 2 

 Eegions ; the 7 classes represent Endlicher's 5 sections ; and the 56 

 alliances are equivalent to the 61 classes in Endlicher's system. 

 733. This division may be presented thus: 



Classes. Wood. Leaves. ttmSaL* Sexes - Embryo. 



Floral 

 Envelopes. 



l.Exogenae Exogenous-Netted Quinary-Perfect Dicotyledonous. 



2. Gymnospermse Exogenous..Parallel or forked.None Imperfect-Dicotyledonous. 



3. Endogense Endogenous.Parallel Ternary. .Perfect Monocotyledonous. 



4. Dictyogense Endogenous.Netted. Ternary-Perfect Monocotyledonous. 



5. Khizauthae None None Variable.Imperfect.Acotyledonous? 



6. Acrogenae Acrogenous.Forked or none. .None None Acotyledonous. 



7. Thallogenae None None None None Acotyledonous. 



734. Henslow has given a comparative view of all these systems, 

 pointing out, in a tabular form, the corresponding divisions in each of 

 them: 



