164 APPENDIX ON PRACTICAL WORK. 
able bark. Leaves generally without a sheath, net-veined. 
Flowers with parts in 4’s or 5’s, or a multiple of those numbers. 
Calyx and corolla usually unlike. Seed, embryo with two coty- 
ledons ; endosperm often absent. 
Sub-class 1.—Incomplete. 
Flowers often unisexual. Calyx inconspicuous or o. Corolla, o. 
Series (1).—-Hypogyne. 
Ovary superior. 
Series (2).— Lpigyne. 
Ovary inferior. 
Sub-class 2.—Polypetale. 
Flowers generally bisexual. Calyx and corolla both present, as a rule, 
the latter polypetalous, and generally bright coloured. 
Series (1).—Thalamiflore. 
Flower hypogynous. Stamens often numerous. 
Series (2).—Calyciflore. 
Flower perigynous or epigynous. Calyx generally gamose- 
palous. 
Sub-class 3.—Gamopetale or Corolliflore. 
Flowers generally bisexual. Calyx generally present, gamosepalous 
Corolla generally present, gamopetalous, and, as a rule, 
brightly coloured. Gynacrwm usually syncarpous. 
Series .1).—Hypogyne. 
Ovary superior. Stamens mostly epipetalous. 
Series (2).—HLpigyne. 
Ovary inferior. 
Having determined the sub-division, class, sub-class, and series to 
which a plant belongs, the next step is to find its natural order or 
family. The following table will enable this to be effected. Details 
are not given of Gymnosperms, and as there are some ninety natural 
orders represented among British Angiosperms, only the most important 
of these can receive notice. 
Crass I.— MONOCOTYLEDONS. 
Sub-class 1.—Nudiflore. 
Series (1.)—Spadiciflore. 
Order 1.—Aroidacez.—Herbs. Leaves, net-veined (N.B. exception 
to rule), Inflorescence, a spadix, often surrounded by a large 
spathe. Jruzt, a berry. 
Exs.—Arum, arum lily (Richardia). 
Order 2.—Lemnacez.—Minute aquatic herbs. Stem,adisc. Leaves, 
o. Flowers, monecious. Stamens, 1. Carpels, 1. 
Exs.—Duckweeds (Lemna and Wolffa). 
Order 3.—Typhacewe.—Erect marsh plants. Inflorescence, spadix 
without aspathe. Flowers, moncecious, male inflorescences upper- 
