Lime. See "Linden." Linden, 195; Fig. 106. Linear, 159. _Linum_, _-aceæ_. See "Flax." Lip, 165. _Liriodendron_. See "Tulip-tree." _Lithospermum_. See "Puccoon." Liverwort, 86. classification of, 91. horned. See "_Anthoceroteæ_." giant, 91; Fig. 57. Lizard-tail, 181, 183; Fig. 97. _Lobelia_, _-aceæ_. 221; Fig. 123. _Loganieæ_, 219. _Lonicera_. See "Honeysuckle." Loosestrife. See "_Lythrum_." swamp. See "Nesæa." Lotus. See "_Nelumbo_." _Lychnis_, 185. _Lycoperdon_, 84; Fig. 49. _Lycopersicum_. See "Tomato." _Lycopodiaceæ_. See "Ground pine." _Lycopodinæ_. See "Club moss." _Lycopodium_, 123. _dendroideum_, 123, 124; Fig. 73. stem and leaves, 123. cones and sporangia, 123. gross anatomy, 123. histology, 124. spores, 124. _Lysimachia_. See "Moneywort." _Lythrum_, _-aceæ_, 206, 228. Mace, 189. _Macrocystis_, 48. Macrospore, 126, 127, 128, 143. _Madotheca_, 86-90; Figs. 52-56. gross anatomy, 86-88. male and female plants, 87, 88. histology of leaf and stem, 88. antheridium, 88, 89. archegonium, 89, 90. embryo, 90. spores and elaters, 90. Magnesium, 2. _Magnolia_, _-aceæ_, 186. Maiden-hair fern, 109-115; Figs. 67-69. general structure, 109. gross anatomy of stem, 110. histology of stem, 110, 111. gross anatomy of leaf, 111. histology of leaf, 111, 112. sporangia, 113, 114. root, 114, 115. apical growth of root, 115. Mallow, 171, 195; Fig. 106. _Malva_, _-aceæ_. See "Mallow." _Mamillaria_, Fig. 112. Mandrake. See "May-apple." Maple, 199; Fig. 108. _Maranta_. See "Arrowroot." _Marattiaceæ_. See "Ringless ferns." _Marchantia_, 91; Fig. 57. breathing-pores, 91. sexual organs, 91. buds, 91. _Marchantiaceæ_, 91. _Marsilia_, 118; Fig. 71. _Martynia_, 218. _Matthiola_. See "Stock." May-apple, 187; Fig. 101. May-weed, 223; Fig. 125. _Medeola_, 155; Fig. 83. Medullary ray, 130, 137. _Melampsora_, 81. _Melastomaceæ_, 206. Melon, 221. _Menispermum_, _-eæ_. See "Moon-seed." _Menyanthes_. See "Buck-bean." _Mesocarpus_, 33; Fig. 19. Mesophyll, 135. Methyl-violet, 4, 233. Micropyle, 180. Microsome, 231. Microspore, 126, 128, 131, 138. Mignonette, 192; Fig. 104. Mildew. See "_Peronospora_," "_Phytophthora_," "_Perisporiaceæ_." Milk-weed, 220; Fig. 122. Milkwort, 199. _Mimosa_. See "Sensitive-plant." _Mimosaceæ_, 209, 210. _Mimulus_, 217. Mint, 181, 215. _Mirabilis_. See "Four-o'clock." Mistletoe, 224. _Mitella_. See "Bishop's cap." _Mitchella_. See "Partridge-berry." Mitre-wort. See "Bishop's cap." Mock-orange. See "_Syringa_." Moneywort, 212; Fig. 117. Monocotyledon, 146, 153, 225, 229. _Monotropa_. See "Indian-pipe," "Pine-sap." _Monotropeæ_, 210. Moon-seed, 188; Fig. 101. Moosewood, 206; Fig. 113. _Morchella_. See "Morel." Morel, 73. Morning-glory, 171, 213; Fig. 118. Morphology, 3. Moss, 5, 86. true, 93. common. See "_Bryaceæ_." peat. See "_Sphagnaceæ_." Moth, 229.