KEY, 225 



640. Perianth regular, the segments either all, or the 

 alternate ones equal 641 



Perianth decidedly irregular; segments, or sepals, 

 of very unequal size and shajDe; or the perianth-tube curi- 

 ously bent 755 



641. Perianth of 3 to 10 divisions or sepals 642 



Perianth (apparently) of 2 sepals. Stamen 1. 



Styles 2, filiform. Fruit indehiscent, nut-like, 4-lobed, 

 4-celled. Flowers polygamous. The solitary stamen in the 

 sterile flowers between a pair of bracts (the apparent peri- 

 anth), in the fertile between the pistil and stem. Other 

 flowers, with 1 stamen and 1 pistil, between 2 bracts. 



Aquatics. Flowers axillary 564 



04^. I. Perianth of 3 segments (lobes or teeth), or 



sepals 643 



II. Perianth of 4 or 5 segments, or sepals 650 



III. Perianth of 6 divisions 701 



IV. Perianth of 7-10 divisions 753 



643, Ovary superior 646 



Ovary inferior 644 



044. Stamens 12, the tips of the filaments usually pro- 

 duced beyond the anther into a point. Perianth 3-cleft or 

 parted, greenish- or brownish-purple. Fruit fleshy, 6-celled, 

 crowned with the calyx, globular. Stemless herbs ; the 

 branched rhizome bearing 2 or 3 long-petioled, kidney- 

 shaped leaves, and a short-peduncled flower, close to the 

 ground. Asarum. 



Stamens 3 645 



04o. Leaves whorled. Corolla 3-cleft. Calyx-limb 

 obscure. Style 1 ; stigmas 2. (534) Galium. 



Leaves alternate. Perianth-tube 3 -sided ; limb 

 3-parted. Stigmas 3. Stems creeping at the base. Leaves 

 lanceolate and serrate, or pectinately dissected. Flowers 

 small, axillary, solitary, or 3-4 together. Proserpinaca. 

 640. Perianth of 3 lance-ovate, awn-pointed, petaloid 

 scales. Stamens 3. Style 3-cleft. Culm leafy. Leaves 

 (parallel-veined) and sheaths hairy. Spikes oblong, clus- 

 tered in heads. (556) Fuirena. 



Perianth not consistinoj of 3 scales 647 



