188 LINN^AN CLASS XIX. 



( 'arex. P'lowers monoecious, rarely dioecious. Stamens usually 3, 

 rarely 1 — 2. Fertile PI. Perigynium membranaceous, 2-toothed, emar- 

 te or truncate, htigmas 2 — 3. Achenium lenticular. Ci/peracea:, 

 111. 



- eria. Staminate flowers. Glumes 2 — G, many-flowered. Paleae 

 without awns. Fertile flow era, Glumes 2 — G, 1 -flowered. Pakta 

 none. Seeds sub-globose. Cyperacecv, 141. 



Tripsaeum. Sterile spikelets in pairs, on each joint of the rachis 

 collateral, 2-flowered ; each with 2 pales. Fertile spikelets solitary, 

 2-flowered. Flowers with 2 paleae; the lower one neutral, upper one 

 fertile Graminaccce, 142. 



Comptonia. Sterile florets in cylindrical aments. Scales 1-flowered. 

 Perianth 2-parted. Stamens 3-forked. Fertile florets in globose heads. 

 Ai/untacece, 115. 



Zea. Staminate flowers in a terminal panicle. Glume 2-flowered, 

 awnless. Pistillate flowers in a lateral compact spike. Style 1, long, 

 filiform, Seed solitary. Graminacea>, 142. 



Tragia. Flowers in spikes. Stamina! ones with perianth 3-parted. 

 Pistillate flowers perianth 5-parted. Capsules 3-celled, 3-seeded. Eu- 

 phurbiacece, 108. 



Order IV.— TETRANDRIA. 



h'rlocaulon. Lachnocaulon. Papalanthus. Flowers in dense heads, 

 sterile florets occupying the center. Perianth 4-parted. Fertile florets 

 in the circumference. Perianth 4-parted. Resiiacecc, 140. 



Alnus. Sterile flowers in a long, cylindrical anient. Scales 3-lobed, 

 3-flowered. Fertile flowers in an ovate ament. Scales 2-flowered. 

 J. AmentaeecB, 115. 



Boehmeria. Sterile flowers with a 4-parted perianth. Fertile flowers 

 with no perianth. Style 1. Nut compressed. Urticacecz, 109. 



Urtica. Sterile flowers with a 4-leaved perianth. Stamens 4. Fer- 

 tile flowers with a 2-leaved perianth. Seed 1, shining. Urticacece, 109. 



Parictaria. Flowers surrounded by a many-cleft involucre. Peri- 

 anth 4-ch'ft. Seed 1, inclosed by the perianth. Urticacecc, 109. 



Moms. Flowers in aments or heads. Perianth usually divided. 

 Fruit a fleshy receptacle covered by numerous achenia. Artocarpa- 

 cecr, 111. 



Paehysandra. Flowers in spikes, the upper sterile, the lower fertile. 

 Perianth Heaved. Styles 3. Capsule 3-horned, 3-celled, 2 6eeds in 

 each cell. Euphorbiaeeae, 108. 



Order V.—PF.NT ANURIA. 



Flowers in spikes. Perianth 5-parted, with 5 petaloid 

 scales, Stigmas B, bifid. Capsule l-seeded, indehiscent Bvphor- 

 b, 108. 

 Amarantkut. Perianth 2 — 6-leaved. styles 3. Ovary l- 



celled, superior, l-seeded. AmartmUutcee^ •".». 



8ch Sepals and petals confounded, roundish, concave. An- 



thera connate. Ovaries numerous, on a conical torus, whieh elongates 

 in maturity. Carpels baccate, 1 -seeded, forming a loose spike. Schi- 

 zaudracece, 4. 



