xx vm 1 



b ANALYTICAL KEY. 



Class II. MONOCOTYLEDONOUS or ENDOGENOUS PLANTS. 



Stems with the wood collected into separate bundles or threads, which 

 are irregularly dispersed throughout the whole diameter, leaving no dis- 

 tinct pith in the centre ; not forming annual layers. (A transverse slice 

 of the stem therefore exhibits the woody threads as dots scattered 

 throughout the cellular tissue.) Leaves mostly parallel-veined (occasion- 

 ally more or less reticulated). Embryo with a single cotyledon, and the 

 first leaves in germination alternate. Parts of the flower generally in 

 threes, never in fives. 



A. Spadiceous Division. Flowers aggregated on a spadlx or fleshy axis, or 

 sometimes scattered, destitute of calyx and corolla {excepting some Araccae, where, 

 however, they are on a spadix) and also of glumes (husky scales). Leaves often 

 luith netted veins. 



Little floating aquatics, with no distinction of stem and foliage. 430 Lemnace;e. 

 Terrestrial or aquatic, with root, stem, and leaves. 



Immersed aquatics, with jointed steins and inconspicuous 



flowers. * 31 Naiadace^;. 



Reed-like or Flag-like marsh or aquatic herbs, with linear 

 and sessile nerved leaves : flowers in spikes or heads. 

 Flowers monoecious : destitute of floral envelopes. . 429 Typhace;e. 

 Flowers perfect, on a lateral spadix : sepals 6. Acorus, -1 

 Terrestrial or marsh plants : leaves mostly with a distinct >■ 426 (80) Arace.*;. 

 netted-veined blade, petioled. J 



B. Petaloideous Division. Flowers not collected on a spadix, furnished with 

 floral envelopes (perianth) ansivering to calyx or to loth calyx and corolla, either 

 herbaceous or colored and petal-like. 



* Perianth adherent to the whole surface of the ovary (superior). 



Flowers dioecious or polygamous, regular. 



Aquatics : ovules and seeds several or numerous. 440 Htdrocharidace^e. 

 Twining plants : ovules and seeds one or two in each 



cell : veinlcts of the leaves reticulated. . 460 (84) Dioscoreaceje. 

 Flowers perfect : ovules and seeds usually numerous or several. 

 Stamens (bearing anthers) only one or two : flower irregular. 



Gynandrous : ovary 1-cclled with 3 parietal placentae. 442 Orchidace^e. 

 Not gynandrous: ovary 3-cellcd. .... (80) Cannace.e. 

 Stamens 3. 



Anthers introrsc, opening transversely. . . 442 Burmanniaceje. 



Anthers introrse or versatile, opening lengthwise. 457 ILemodorace;e. 



Anthers extrorse, opening lengthwise. . . 459 (82) Iridace^;. 



Stamens 6 : flowers usually on a scape from a bulb. 455 (80) Amaryllidaceje 



