484 PART IV. CLASSIFICATION. 



large green spathe completely envelopes the spadix (Fig. 295). Dracun- 

 culus and Arisarum are also European genera. 



Order 2. LEMNACE^E. Stem leafless. Each, inflorescence con- 

 sists of two <$ flowers and one $ flower borne on a lateral branch 

 of the stem : the flowers consist of a 

 single stamen, and the ? flower of one 

 carpel. 



Lemna trisulca, L. (Synrodela) polyrhiza, minor 

 and ffibba, are known as Duck-weed ; they are 

 common in tanks and ponds, floating on the 

 water. The stem, which is leafless, is almost 

 flat, resembling a thallus : it bears two rows of 

 branches (Fig. 296), as also roots on its under 

 FIG. 296, Part of a plant surface which are suspended in the water, 

 of Lemna trisulca, seen from Hoots are, however, absent in Wdffia arrhiza, 

 above: a the young lateral which is algo devoid of vascu l ar bundles; its 

 flower has no spathe, and it bears only one row 

 of branches : it is the smallest known flowering plant. 



Order 3. TYPHACE.E. Flowers diclinous ; the perianth repre- 

 sented only by scales, or 0. Stamens usually 3. Ovary usually 

 monomerous, containing one ovule. Inflorescence a spadix, without 

 a spathe,. elongated or compact. 



In Sparganium, the Bur-Reed, the inflorescences are spherical spikes 

 which are borne terminally and laterally in two rows on the upper part 

 of the stem. The lower spikes bear only <j> , and the upper only J flowers : 

 the perianth consists of 3-6 scales ; stamens 3-8, free ; gynseceum some- 

 times dimerous with an ovule in each loculus. Sparganium simplex and 

 ramosum are not rare in ditches. 



Typha, the Reed-Mace or Bulrush, bears its flowers on a long terminal 

 spadix ; the $ flowers are borne directly on the upper and thinner portion 

 of the main axis ; on the lower and thicker portion are borne the ? flowers, 

 partly on the main axis and partly on very short lateral shoots ; the 

 perianth is replaced by long hairs *, stamens 15, monadelphous. Typha 

 angustifolia and latifolia occur in bogs and wet places. 



Cohort II. Pal males. Order 1. PALMACE^E. The dioecious 

 or monoecious, rarely moncclinous or polygamous, flowers are in- 

 serted, with or without bracts, on the spadix or on the thick axis 

 of a spicate or paniculate inflorescence (Fig. 297) : they generally 

 conform to the type -BT3, C3, ^43 + 3, G -' : in some instances a 

 larger or a smaller number of stamen's are present : anthers some- 

 times introrse : carpels rarely more or less than 3, either free or 

 connate ; when the gynseceum is apocarpous, the ovary is unilocu- 



