122 PB ACTIO AL GUIDE TO GARDEN PLANTS 



seed vessel, or fruit. It is this latter characteristic that gives the 

 name to the group, the word ' angiosperm ' being derived from 

 ' angios,' hidden, and ' sperma,' a seed. 



(ii.) GYMNOSPERMS.— In these plants the flowers are 

 strictly unisexual, that is either all female or all male, and the 

 perianth, ovary, and styles are absent. The ovules are naked 

 (not enclosed in carpels), and are fertilised by direct contact 

 with the pollen, and not by means of a pollen tube (see p. 24) . 

 Cotyledons (seed-leaves) 2, or sometimes in whorls of 3 or more. 

 Natural Orders with these Characters. — Gnbtace^, p. 972, CoNi- 

 FEE^, p. 972. 



The Angiosperms (or plants having their seeds enclosed in an ovary) 

 are also divided into two main groups or sub-classes, viz. : — 



1. Dicotyledons (p. 131) and 2. Monocotyledons (p. 805), the 

 characters of which are given below with the various groups belonging 

 to them. 



Sub-Class I. DICOTYLEDONS (p. 131 to p. 805). 



The plants belonging to this group are described in this work from 

 p. 131 to p. 805, and are characterised by having stems with bark, pith, 

 and wood, and when perennial, increasing in diameter by an annual 

 layer of wood added to the outside of the old wood, and another of 

 bark to the inside of the old bark. Leaves usually vdth netted veins. 

 Flowers with the parts usually in fours or fives, and usually with 

 a distinct perianth. Ovules in closed carpels, through the tissues 

 of which the pollen tube passes to effect fertilisation as described at 

 p. 24. Embryo with 2 cotyledons or seed leaves. 



Dicotyledons are subdivided into 3 main divisions, viz. : — 1. Poly- 

 petalcB ; 2. Disciflorce ; and 3. Galyciflorce, each of which is again 

 subdivided into series, cohorts, and natural orders as below. 



Division I. POLYPETALM (p. 131 to p. 477). 



Flowers with both calyx (sepals) and corolla (petals) . Petals free 

 or distinct from each other. 



Series I. Thalamifloe.iE (p. 131 to p. 284). 

 Sepals usually free. Petals definite, often numerous. Stamens 

 inserted on a torus or receptacle, hypogynous, numerous or definite. 

 Ca/rpels free (apocarpous) or united {syncarpous). 



Cohort 1 . Eanale s (carpels usually free) . — Stamens numerous. 

 Perianth consisting of calyx only, or of calyx and corolla. 



Natural Orders with these Characters. — Eanunculacb^ 

 (p. 131), CalycanthacejE (p. 172), MAGNOLiACEiE (p. 173), Ano- 



