ARTIFICIAL KEY TO THE NATURAL ORDERS. XX1U 



B. Flowers (monacious or diozdous) one or both sorts in catkins. 



* Only one sort of flowers in catkins or catkin-like heads. 



fertile flowers forming a short catkin or strobile in fruit. Humulus in URTICACE2E, 394 



Fertile flowers single or clustered : sterile ones in slender catkins. 



Nut in an involucre or cup. Leaves simple. CUPULIFER.33, 403 



Dry drupe naked, with no involucre. Leaves pinnate. JUGLANDACHE, 401 



* * Both the sterile and fertile flowers in catkins or heads. 



Fruit a thin dehiscent pod. Seeds numerous, downy-tufted. SALICACE^l, 413 

 Fruit a woody pod. Seeds naked. Liquidambar in HAMAMELACHaE, 148 



Fruit a berried drupe or drupe-like. Ovary 1-celled, 1-ovuled. 4 



Parasitic : leaves opposite, thick. LORANTHACE.33, 382 



Not parasitic : leaves alternate, fragrant. MYRICACE^, 409 

 Fruit, i. e. the pericarp itself, a nutlet or achenium. 



Nutlets winged or oblong, under dry or woody scales. BETULACEJ3, 410 



Nutlets club-shaped, naked, plumose-hairy below. PLATANACE2E, 400 



Achenia thin, surrounded by an herbaceous or often juicy calyx. URTICACILE, 394. 



SUBCLASS II. GYMNOSPERM^. Pistil an open scale or altered 

 leaf, bearing naked ovules on its margin or upper surface, or in Taxus 

 entirely wanting. 

 Flowers monoecious or dioecious. Stems branched. Leaves simple. CONIFER2E, 420 



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. Leaves mostly paral- 

 lel-veined. Embryo with a single cotyledon, and the first leaves alternate. 

 Parts of the flower generally in threes. 



A. Flowers destitute of any proper floral envelopes (either calyx or corolla), and also of glumes 

 like those of Grasses and Sedges, mostly aggregated on a spadix. 



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



Fruit a 1 -lew-seeded berry. Spathe conspicuous. ARACEJE, 426 



Fruit a dry nutlet. Flowers densely spiked or capitate. Marsh herbs. TYPHACEJ3, 429 



Fruit a nutlet, drupe, or utricle. Immersed aquatics. NAIADACEJS, 431 



2. Floating free : no distinction of stem and foliage. 



Flowers bursting from the edge of a floating frond. LEMNACEJ3, 430 



B. Flowers with true floral envelopes (perianth) representing the calyx or calyx and corolla. 

 L Flowers densely crowded on a spadix. Certain ARACHE, 426, and NAIADAGEJE, 431 



2. Flowers solitary, clustered, or variously disposed, but not collected on a spadix. 



* Perianth adherent to the ovary or to its base. 

 Flowers dioecious or polygamous, regular. 



Aquatics. Fruit fleshy, indehiscent. HYDROCHARIDACE^E, 440 



Climbers, veiny-leaved. Pod 3-winged. DIOSCOREACE^E, 460 



Flowers perfect. (Pod several - many-seeded ) 



Stamens 1 or 2, gynandrous. Pod 1-celled with 3 parietal placentae. ORCHIDACE^, 442 

 Stamens 8, before the outer divisions of the perianth : anthers extrorse. IBID ACEJB, 459. 

 Stamens 3, before the inner divisions of the perianrh: anthers introrse. 

 Filaments very short, included. f BUBMANNIACEJ3, 442. 



Filaments elongated, exserted. \ 



,. _ . .. ' (. 



Stamens to. Perianth free, except at the base, J 



