Rhizome. See "Root-stock."

_Rhododendron_, 210; Fig. 116.

_Rhodophyceae_. See "Red algae."

_Rhodoraceae_, 211.

_Rhoeadinae_, 190.

_Rhus_. See "Sumach."
_cotinus_. See "Smoke-tree."
_toxicodendron_. See "Poison-ivy."
_venenata_. See "Poison-dogwood."

_Ribes_, _-ieae_, 203; Fig. 111.

_Ricciaceae_, 91; Fig. 57.

_Richardia_. See "Calla."

_Ricinus_. See "Castor-bean."

Ringless-fern, 116.

Rock-rose, 195.

Rock-weed. See "_Fucus_."

Root, 102, 104, 114, 173.

Root-cap, 115, 175.

Root-hair, 38, 87, 91, 96, 104, 135.

Root-stock, 154, 172.

_Rosa_, _-aceae_. See "Rose."

Rose, 181, 206; Fig. 114.

_Rosiflorae_, 206.

_Rubiaceae_, 223.

Rush, 154, 225; Fig. 83.

Rust, white. See "_Cystopus_."
red. See "_Uredineae_."
black. See "_Uredineae_."

_Sabal_. See "Palmetto."

_Sabbatia_. See "Centaury."

_Saccharomycetes_. See "Yeast."

Sac fungi. See "_Ascomycetes_."

Safranine, 233.

Sage, 215; Fig. 120.

_Salicineae_, 183.

_Salix_. See "Willow."

_Salvinia_, 118.

_Sambucus_. See "Elder."

_Sanguinaria_. See "Blood-root."

_Sapindaceae_, 199.

_Saprolegnia_, _-aceae_, 60-62; Fig. 36.
zooespores, 62.
resting spores, 62.
antheridium, 62.

_Sargassum_, 48; Fig. 28.

_Sarracenia_, _-aceae_. See "Pitcher-plant."

Sassafras, 188.

_Saururus_. See "Lizard-tail."

Saxifrage, 202.

_Saxifraginae_, 202.

_Scabiosa_. See "Scabious."

Scabious, 224.

Scalariform, 110.

Scale-leaves, 170.

_Scenedesmus_, 24; Fig. 11.

_Schizomycetes_. See "_Bacteria_."

Schizophytes, 12, 14.

Schlerenchyma. See "Stony tissue."

_Schrankia_. See "Sensitive-brier."

_Scilla_, 151.

_Scirpus_. See "Bulrush."

_Scitamineae_, 153, 162.

Scotch pine, 129-140; Figs. 75-77.
stems and branches, 129.
leaves, 129, 130.
gross anatomy of stem, 130.
growth-rings, 130.
roots, 131.
sporangia, 131.
cones, 132.
macrospores and prothallium, 133.
ripe cone and seeds, 133.
germination, 134.
young plant, 134.
histology of leaf, 135.
of stem, 136-138.
of root, 138.
microsporangium and pollen spores, 138, 139.
archegonium, 140.
fertilization, 140.

Scouring-rush, 122.

_Scrophularia_, _-ineae_. See "Figwort."

Sea-lettuce, 26; Fig. 15.

Sea-rosemary, 212.

Sea-weed (brown). See "Brown algae."
(red). See "Red algae."

Sedge, 161; Fig. 87.

_Sedum_. See "Stonecrop."

Seed, 128, 133, 145, 150.

Seed-plan