Introduction. xxiii 



Trees, shrubs, or herbs with more or less conspicuous unisexual or bi- 

 sexual flowers and seeds containing a distinct embryo 



Phcenogamous Plants, 1 



Trees or herbs (Ferns, Horsetails, Mosses, Seaweeds, Fungi, &e.), 

 without staminate or pistillate flowers ; seeds (spores) destitute of 

 an embryo . . . . . Cryptogamous Plants, p. 542 



'Stem when perennial consisting of a central pith, concentric layers of 

 wood, and a separable bark, increasing in size by the formation of 

 additional layers beneath the bark, the latter expanding or renew- 

 ing itself in proportion to the growth of wood. Leaves net-veined. 

 Parts of the flower free or united, usually in fours or fives or 

 some multiple of these numbers. Floral envelopes when present 

 consisting of a distinct calyx and corolla, the former usually green 

 and the latter coloured ; or all the series similar, and then termed 

 a perianth ; or the sexual organs without any distinct whorl of 

 investing organs, though sometimes subtended by bracts. Seeds 

 with two opposite entire or divided cotyledons . Dicotyledons, 2 



Stem destitute of central pith, not increasing in diameter by annual 

 layers, vascular bundles irregularly scattered amongst the cellular 

 tissue. Leaves usually parallel-veined (or rarely net- veined, as in 

 the Aroideae, Smilacinese, and one or two other orders). Parts of 

 the flower usually in threes. Floral envelopes in one or two 

 series, free or united in some degree, usually all coloured and 

 similar in form, sometimes reduced to scales or scaly bracts, as in 

 Grasses and Sedges. Seeds with one cotyledon . Monocotyledons, 3 



Ovules enclosed in an ovary (all orders excepting Coniferse and 



Gnetaceae) . ''*" . . . . . . Angiospernus, 4 



j Ovules not enclosed in an otary . Gymnospermee (Conifers and Gnetacece) 



p. 419-457 

 Petals when present free to the base or very slightly united, -as" in some 



Malvacese . ' . ', '. Polypetalce, p. 1 



Petals usually united, forming a monopetalous corolla, or rarely 



almost free, as in some Ericaceae . . . Gamopetalce, p. 218 

 Petals none (in the plants described in this work). Perianth usually 

 inconspicuous, sometimes coloured, as in Mirabilis ; or none, as 

 in the Cupuliferse, Coniferse, etc. . . ; . ; Apetalce, p. 382 



|" Perianth usually composed of six segments in two whorls, all or some 

 of them coloured, rarely green. Some of the plants belonging 

 to this division have small inconspicuous flowers, destitute of a 

 regular perianth, e.g. Aroidese, Typhacese . ' : \ . Petaloideee, p. 458 

 Perianth none, or reduced to minute scales. Flowers often arranged 

 in spikelets, and enclosed in imbricated membranous or coria- 

 ceous bracts, termed glumes. Fruits (in the orders referred to 

 in this work) 1 -celled, 1 -seeded, the perianth-scales usually 

 adhering to the fruits Glumiferee, p. 537 



SUB-CLASS I DICOTYLEDONS OR EXOGENS. 

 1. Flowers having both calyx and corolla ; petals free, 



A. Stamens more than twenty. 

 Ovary inferior or partially so. 



