Plants

Plants

Trees 
Wildflowers (Herbs)

Ferns 

Grasses 

Mosses 

Algae 

Edible Plants

Ontario Field Naturalist's Toolchest
Classification of Plants
Vascular Plants Non-vascular
Woody Trees
Shrubs
Herbs
Mosses Mosses
Liverworts
Hornworts
Ferns Ferns 
Horsetails
Club-Mosses
Algae  
Grasses Grasses
Sedges
Rushes
   

Plants 
Forest Plants of Central Ontario Wetland Plants of Ontario Manual of Vascular Plants of Northeastern United States and Adjacent Canada Illustrated Companion to Gleason and Cronquist's Manual
Forest Plants of Central Ontario Pub GB
Covers common trees, wildflowers, ferns, grasses, sedges, clubmosses, horsetails, mosses,  lichens and more.    There is an edition for Northeastern Ontario as well.  None for southern or western Ontario though.
Wetland Plants of Ontario GB
Similiar to Forest Plants of Cental Ontario but focuses on wetlands and covers all of Ontario.
Manual of Vascular Plants of Northeastern United States and Adjacent Canada Am GB
Covers all our vascular plants (woody plants, ferns and grasses but not mosses and their allies).  A comprehensive book that is rather scientific, expensive and recommended only for advanced plant enthusiasts.  
Illustrated Companion to Gleason and Cronquist's Manual GB
The manual of vascular plants is primarily a key and this book provides illustrations to make it easier to use.

The Book of Forest and Thicket The Book of Swamp and Bog The Book of Field and Roadside Winter Botany A Naturalists Guide to Field Plants
The Book of Forest and Thicket GB
The Book of Swamp and Bog GB
The Book of Field and Roadside GB
The coverage of these three books is eastern North America.  These books are not field guides in the conventional sense. Only common plants are covered but the write ups on each plant is superb.  The write ups explores the connections between plants, bugs and their habitats. This makes these books more interesting than typical field guides and is likely to attract interest from bugsters.  
Winter Botany GB
In the wintertime not much is going on in nature so for people interested in plants Winter Botany might cure the winter blues..
A Naturalists Guide to Field Plants GB

General natural history of plants.
The Vascular Plants of Bruce Penisula The Flora of Manitoulin Island
The Vascular Plants of the Bruce Peninsula, Ontario Blog Am
The Flora of Manitoulin Island (third edition) Pub
Vascular Plants of Thickson's Woods Pub


Plants Of The Kingston Region Plants of Quetico and the Ontario Shield Checklist of Vascular Plants of Thunder Bay District Flora of North America Series Tallgrass Prairie Wildflowers: A Field Guide to Common Wildflowers and Plants of the Prairie Midwest
Plants Of The Kingston Region GB
Plants of Quetico and the Ontario Shield GB 
Two different regional plant guides
Checklist of Vascular Plants of Thunder Bay District Pub
Flora of North America (Series) Pub
A series of book and a website on all the flora of North America.
Tallgrass Prairie Wildflowers: A Field Guide to Common Wildflowers and Plants of the Prairie Midwest GB
Common flowers seen in tallgrass prairie, an rare habitat in Ontario.

Michigan Flora: Upper Penisula
Wetland Plants of Wisconsin
Wetland Plants of Michigan
A Great Lakes Flora
Bogs & Fens: A Guide to the Peatland Plants of the Northeastern United States and Adjacent Canada

Michigan Flora Am
Wetland Plants of Wisconsin Am 
Wetland Plants of Michigan Am
A Great :Lakes Wetland Flora Am
Bogs & Fens: A Guide to the Peatland Plants of the Northeastern United States and Adjacent Canada Am


The Big, Bad Book of Botany GB
A Naturalist's Guide to Field Plants: An Ecology for Eastern North America GB
A Naturalist's Guide to Wetland Plants: An Ecology for Eastern North America GB
A Naturalist's Guide to Forest Plants: An Ecology for Eastern North America GB

Some websites on plants in general:
Northern Ontario Plant Database Extensive, southern limit of coverage is North Bay, Ontario.
Muskoka Flora An Annotated Checklist of Vascular Plants
University of Guelph Arboretum 
Fowler Herbarium at Queen's University 
Andy's Northern Ontario Wildflowers Has nice habitat pictures and includes info on mosses, fungi, mushrooms, lichen and ferns.
Wildflowers of Ontario
Ontario Weeds
Michigan Flora - University of Michigan Herbarium
Southern Ontario Vascular Plant Species List Omits some northern and western species (about 500 out of 3400)  but otherwise a fairly complete list of plants for Ontario.  3rd edition, 2013
Identification Of Major Fruit Types
Go Botany: Discover Thouands of New England Plants
Canadian Museum of Nature - Our Collections - Search
Collector A collector search engine. Information about collectors for specific plants.  Use after searching the link above
Native Plants Database

iPhone apps:
Florafolio
Botany Buddy  
In particular, iPhone apps for plants like these two could be the field guide of choice to plants.  But their databases needs much more information if they are to replace paper field guides.

Trees 
Trees In Canada Trees and Shrubs Shrubs of Ontario Ontario's Old Growth Forests Bark: A Field Guide to the Trees of the Northeast
Trees In Canada Am GB
The recommended book for trees.
Trees and Shrubs GB
Also quite good.
Shrubs of Ontario Am
The only book on shrubs for Ontario.
Ontario's Old Growth Forests Pub Am
A field guide not on trees but where you can find pockets of the oldest forests in Ontario.
Bark: A Field Guide to the Trees of the Northeast Pub Am



Trees of Ontario Remarkable Trees of the World Tree Identification Book Field guide to native oak species of eastern North America Wildberries of Ontario

Trees of Ontario Pub GB
An OK field guide to trees.
Remarkable Trees of the World Am GB
Features many of the oddest trees in the world.
Tree Identification Book GB
An older tree identification guide.
Field guide to native oak species of eastern North America GB(Full text)
We only get a few species of oak but you can see this book in its entirety.
Wildberries of Ontario Pub
Trees of Eastern North America

Trees of Eastern North America
GB

State of Eastern Ontario's Forests Three printable keys: a coniferous and a winter and summer deciduous key.
Upper Peninsula TREE  IDENTIFICATION  KEY Good online key but Michigan based.
Ontario Trees and Shrubs Walter Muma's site on trees and shrubs.
Leafsnap A field guide to leaves, flowers and fruits of trees that is available online and as an app.  Misses some Ontario species but well presented.
Tree Diseases of Eastern Canada PDF
Field Guide to Tree Diseases of Ontario PDF These two books on trees diseases are rather similiar
Diseases of Trees and Shrubs For North America

Wildflowers 
Newcomb's Wildflower Guide A Field Guide to Wildflowers Botany in a Day: The Patterns Method of Plant IdentificationPlants of Southern Ontairo
Newcomb's Wildflower Guide GB Am
Interesting key system.  You create a three digit key out of flower type, plant type and leaf key.  Then you follow, if necessary, a standard dichotomous the rest of the way.  The most useful wildflower guide.
A Field Guide to Wildflowers GB
Color based guide.  Great, but requires a lot of page flipping.
Botany in a Day: The Patterns Method of Plant Identification Am
Useful anywhere in the world.  Teaches how to identify plant families.
Plants of Southern Ontario Am

ROM Guide to the Wildflowers of Ontario Ontario Wildflowers: 101 Wayside Flowers A Guide to Wildflowers in Winter Wildflowers and Winter Weeds

ROM Guide to the Wildflowers of Ontario GB
Comprehensive and the only one with range maps. Ranges of plants in Ontario are poorly known so the range maps are fairly crude.
Ontario Wildflowers: 101 Wayside Flowers Pub GB
A beginner's guide to wildflowers.  Not many species are covered.
A Guide to Wildflowers in Winter GB
Wildflowers and Winter Weeds GB
These last two books may cure the winter blues of some wildflower fanatics.  The first one is northeastern North America based and the second is based in Michigan.

The Asters, Goldenrods, and Fleabanes of Grey and Bruce Counties The Goldenrods of Ontario The Asters of Ontario
The Asters, Goldenrods, and Fleabanes of Grey and Bruce Counties Pub GB
This book does these types of wildflowers best.  Don't bother trying to learn the difficult to identify asters and goldenrods without them.  Note that it is regional and doesn't cover all the species of these wildflower families.
The Goldenrods of Ontario Review GB
The Asters of Ontario Review GB
These two books are more technical and are recommended if you are really into goldenrods and asters.
Aster in Wisconsin PDF Pictures of the flowers in the genus aster
Solidago & relatives in Wisconsin PDF Same for the goldenrods
Keys to the asteraceae of Wisconsin Keys to the entire composite family

A Guide to the Orchids of Bruce and Grey Counties The Wild Orchids of North America, North of Mexico Native Orchids of North America North of Mexico Orchids of the Western Great Lakes Region Ontario Weeds
A Guide to the Orchids of Bruce and Grey Counties Pub GB
A local guide to orchids from the hotspot for orchids in Ontario.  Most of Ontario's species are covered.
The Wild Orchids of North America, North of Mexico GB
Native Orchids of North America North of Mexico GB
Two North American book on orchids.  
Orchids of the Western Great Lakes Region GB
Ontario Weeds Pub
Weeds of North America Weeds of the Northeast
Weeds of North America Am
Weeds of the Northeast Am

Websites on wildflowers include:
Ontario Wildflowers variety of resources about wildflowers including a forum.
Andy's Northern Ontario Wildflowers has nice habitat pictures and includes info on mosses, fungi, mushrooms, lichen and ferns. 
Wildflower Identification a engine to identify wildflowers and has quizzes to help you.
Wildflower Photos  is a field guide to wildflowers of far eastern Ontario.
Goldenrods of the Ottawa Region
Cinquefoils of the Ottawa Region
Asters of the Ottawa Region
Violets of the Ottawa Region
Wild Orchids of Northern Ontario Doug Adams, a lodge operator has a mini field guide to the orchids -- many rare -- he found in Temigami.  He is up to 22 species as of 2009 and could find even more in 2010.
Native Orchids of Canada
Sparganium identification key and species descriptions Keys to the small bur-reed family for Wisconsin.  Covers most if not all of Ontario's species (it covers all six for Algonquin Provincial Park)
Sparganium Research Page Parent page to Sparganium identification key
 
Ferns 
The Ferns of Grey and Bruce Counties Peterson Field Guide to Ferns, Second Edition Fern Finder A Natural History of Ferns Ferns of the Northwoods
The Ferns of Grey and Bruce Counties Pub GB
The recommended beginner's book to ferns.  Covers most of the ferns of Ontario
Peterson Field Guide to Ferns, Second Edition GB
Covers the rest of the ferns of Ontario, and is another recommended book.
Fern Finder GB
Good for beginners, easy to carry.
A Natural History of Ferns GB
Very few books cover the natural history of ferns, but this one does.
Ferns, Horsetails & Clubmosses of the North Woods Am
May be more appealing and easy to use for some people than the Peterson's guide as it has over 250 photographs.  But it may miss some Ontario species.


Midwest Ferns Northeast Ferns Henry Potters Field Guide to the Hybrid Ferns of the Northeast Ferns and fern allies of Canada Fern and Fern Allies of Canada

Midest Ferns Am
Northeast Ferns Am
Henry Potters Field Guide to the Hybrid Ferns of the Northeast Am
Ferns and fern allies of Canada  Archive
Ferns and fern allies of Canada Am Updated.  Both books include distriubtion maps
Ontario Ferns A website on ferns, horsetails and club-mosses.
Ferns and Fern Allies of Wisconsin
Ferns of the Ottawa District (PDF)

Grasses 
Grasses: An Identification Guide How to Identify Grasses and Grass-like Plants Grasses of Ontario Field Guide to Wisconsin Sedges Field Guide to Wisconsin Grasses
Grasses: An Identification Guide GB
The recommended guide.
How to Identify Grasses and Grass-like Plants Review Am
Also recommended.
Grasses of Ontario GB PDF
Out of print but useful for its range maps.
Field Guide to Wisconsin Sedges GB
As Ontario doesn't have a field guide to sedges, this one from nearby Wisconsin will do.
Field Guide to Wisconsin Grasses GB
Manual of Grasses for North America GB

Grasses of the Northeast

Grasses of the Northeast: A Manual of the Grasses of New England and Adjacent New York Am

Ontario Grasses On grasses, sedges and rushes.
Grasses in North America A detailed guide to the grasses of North America north of Mexico.  Includes range maps, illustrations, images and other information.  Incomplete and illustrations are small.
Tallgrass Ontario Resources on a rare habitat in Ontario.
Poaceae
 
Mosses 
A Graphic Guide to Ontario Mosses Common Mosses of the Northeast and Appalachians
Outstanding Mosses & Liverworts of Pennsylvania & Nearby States Field Guide to the Peat Mosses of Boreal North America Elfin World of Mosses and Liverworts

A Graphic Guide to Ontario Mosses Pub GB
An overview of Ontario mosses.  Know this book well before proceding further as there are few other friendly field guides (with the exception of the next one).
Common Mosses of the Northeast and Appalachians Am GB
Nicest field guide, and the best you can get before heading towards the technical books.
Outstanding Mosses & Liverworts of Pennsylvania & Nearby States Am
Field Guide to the Peat Mosses of Boreal North America Am GB
Covers spaghum mosses only but has color plates.
The Elfin World of Mosses and Liverworts of Michigan's Upper Peninsula and Isle Royale GB Am
Not quite Ontario, but is for the layman.  Color photographs included.  Cover 123 species of mosses and liverworts.  Isle Royale is a large island in the middle of Lake Superior.

Mosses of the Great Lakes Forest Mosses of Eastern North America Checklist of the Mosses of Ontario Mosses, Liverworts, and Hornworts A Field Guide to Common Bryophytes of the Northeast

Mosses of the Great Lakes Forest Pub GB Am
Comprehensive.
Mosses of Eastern North America GB
Comprehensive but for a larger geographic area than the similar preceding one.
Checklist of the Mosses of Ontario GB
Mosses, Liverworts, and Hornworts: A Field Guide to Common Bryophytes of the Northeast Pub

Gathering Moss: A Natural and Cultural History of Mosses The Structure and Life of Bryophytes
An Enthusiasts Guide to the Liverworts and Hornworts of Ontario
Liverworts of New England: A Guide for the Amateur Naturalist Mosses Lichens & Ferns of Northwest North America

Gathering Moss: A Natural and Cultural History of Mosses GB
A natural history book on mosses.
The Structure and Life of Bryophytes GB
Another natural history book on mosses but more technical.
An Enthusiasts Guide to the Liverworts and Hornworts of Ontario Pub 
The book for the close relatives of mosses.  First half is a key, second half has species descriptions with line drawings on the facing page.  Six pages of color photographs. Spiral bound paperback
Liverworts of New England: A Guide for the Amateur Naturalist Am
Mosses Lichens & Ferns of Northwest North America GB

World of Mosses Robert Muma's website is quite an interesting introduction to the subject of mosses. His field guide A Graphic Guide to Ontario Mosses is available online or in book form.  The book is not professionally bound (it is 8 pages printed out, folded in half with two staples with a green cover) but the information inside is valuable.
Bryophyte Flora of North America A comprehensive website on mosses, liverworts and hornworts of North America.
A Perspective Oriented Guide for the Identification of North American Bryophyte Genera

Algae
Algae are the least known of the plants.  To really study them you do really need a microscope and go through rather technical field guides.  Small organisms like algae offer the opportunity to bring nature appreciation indoors as you study them through a microscope.  Not many books have been published on the subject.
Freshwater Algae How to Know the Freshwater Algae How to Know the Seaweeds Freshwater Algae of North America Diatoms of North America
Freshwater Algae GB
How to Know the Freshwater Algae
GB
How to Know the Seaweeds GB
Good but dated field guides.
Freshwater Algae of North America GB
Comprehensive and technical.
Diatoms of North America GB
Short book on a type of algae.
 
Common Freshwater Algae of the United States
Common Freshwater Algae of the United States: An illustrated Key to the Genera (Excluding the Diatoms) GB

Freshwater algae General key to freshwater algae. 

Edible Plants 
A Field Guide to Edible Wild Plants: Eastern and central North America The Encyclopedia of Edible Plants of North America A Field Guide to Medicinal Plants and Herbs: Of Eastern and Central North America
A Field Guide to Edible Wild Plants: Eastern and central North America (Peterson Field Guides) GB
The Encyclopedia of Edible Plants of North America GB
A Field Guide to Medicinal Plants and Herbs: Of Eastern and Central North America (Peterson Field Guides)  GB