Aquatic plants fo the Pacific Northwest with vegetative keys

192 Pages·2013·2.47 MB·English

by  Steward, Albert N.

OREGON STATE MONOGRAPHS
Studies in Botany
FRANK H. SMITII, Ph.D., Consulting Editor
Aquatic Plants of the Pacific Northwest
With Vegetative Keys
STUDIES IN BOTANY
Number 11
i
Studies in Botany
1. Tuberales of North America, by Helen M. Gilkey
2. Developmental Morphology of Alpova, by S. M. Zeller
3. Paleoecology of Two Peat Deposits on the Oregon Coast, by Henry P. Hansen
4. Moss Flora of the Willamette Valley, Oregon, by Clara J. Chapman and Ethel I.
Sanborn
5. Floral Anatomy of the Santalaceae and Some Related Forms, by Frank H. Smith
and Elizabeth C. Smith
6. Septoria Disease of Gramineae in Western United States, by Roderick Sprague,
Ph.D., Pathologist
7. Clavaria, the Species from Oregon and the Pacific Northwest, by Maxwell S. Doty
8. The Marine Algae of the Coos Bay-Cape Arago Region of Oregon, by Ethel I.
Sanborn, and Maxwell S. Doty
9. Northwestern American Plants, by Helen M. Gilkey
10. Species of Selenophoma on North American Grasses, by Roderick Sprague, and
A. G. Johnson
11. Aquatic Plants of the Pacific Northwest with Vegetative Keys, by A. N. Steward,
La Rea Dennis, and Helen M. Gilkey
ii
Aquatic Plants of the Pacific Northwest
With Vegetative Keys
By
ALBERT N. STEWARD
Formerly Associate Professor of Botany
Associate Botanist, Agricultural Experiment Station, Oregon State College
LA REA J. DENNIS
Instructor in Botany, Curator of Herbarium, Oregon State College
HELEN M. GILKEY
Professor Emeritus of Botany, Oregon State College
STUDIES IN BOTANY NUMBER 11
OREGON STATE COLLEGE
CORVALLIS, OREGON
1960
iii
TABLE OF CONTENTS
Page
Key to Families
3
Descriptive Flora
19
Glossary 165
Bibliography 171
Index
173
PLATES
Page
Plate I 26
Plate II
37
Plate III
48
Plate IV
56
Plate V
73
Plate VI
83
Plate VII
93
Plate VIII
96
Plate IX
104
Plate X 110
Plate XI
116
Plate XII
120
Plate XIII
125
Plate XIV
134
Plate XV 138
Plate XVI
143
Plate XVII
147
Plate XVIII
152
Plate XIX
158
Plate XX
164
Printed at the College Press
Oregon State College
iv
PREFACE
With the support of the National Science Foundation, the late Dr. Albert
N. Steward started work on vegetative keys to the aquatic plants of the Pa-
cific Northwest ; his untimely death in June of 1959 made it necessaryfor as-
sociate authors to be named to continue the project.
The area included in this study is Oregon, Washington, British Colum-
bia, and Alaska. Considerable difficulty was encountered in preparing a list of
plants to be included. An effort was made to include all true aquatics and also
species whose life cycle includes some stage that requires either the saturation
of the substrate with water or the presence of an ambient aqueous medium.
The intent has been to exclude species occasionally found in moist places but
equally at home in drier situations.
In the Pacific Northwest the period of flowering and fruiting of aquatic
plants is very short when compared to the long period of vegetative develop-
ment experienced by a large proportion of the species. Many species appear
not to flower every year but may appear prominently in the flora vegetatively
for ten to twelve months of each year. This situation makes it most desirable
that the keys be constructed primarily upon vegetative characters. This has
been the approach wherever possible in this study. Reproductive characters
have often been given as secondary characteristics to supplement and
strengthen the keys. Where species are not readily distinguishable vegetatively,
inserts were made in the key making separations on reproductive characters.
Numerous individuals have helped in the preparation of this manuscript ;
to them the authors express their genuine appreciation. Special mention should
be made of the National Science Foundation for making the study financially
possible; Dr. Roy A. Young, head of the Department of Botany and Plant
Pathology for encouragement and consideration; Dr. Harry K. Phinney for
advanced testing of the key to families in his class and for valuable sugges-
tions; Dr. Frank H. Smith for critical editorial and technical assistance; and
Mrs. Catherine Davis Young for most of the detailed drawings.
February 18, 1960

Aquatic Plants of the Pacific Northwest
With Vegetative Keys

KEY TO FAMILIES
Page
la. Plants not differentiated into true roots, true stems, true leaves, not possessing
true vascular tissue, the plant body therefore a thallus ; gametophytic thallus
often producing structures superficially resembling roots, stems, and leaves ;
reproduction vegetative and/or by spores [BRYOPHYTA]
2a. Gametophytic thallus radially symmetrical; leaf-like structures scale-
like and overlapping [MUSCI]
3a. Plants with long stem-like structures floating out from the point
of attachment, green in color
__species of Fontinalis and Dichelyma FONTINALCEAE 22
3b. Plants with rather short stem-like structures forming thin mats
on rocks or soil, or the mats rarely floating; or forming dense
cushion-like mats in bogs.
4a. Color of the plants grayish-green; a thick cushion-like mat
in bogs Sphagnum SPHAGNACEAE 23
4b. Color of plants yellow-green, brownish, or nearly black ;
thin mats covering rocks or soil, or the mats rarely float-
ing in fresh water streams species of Leptodictyum,
Drepanocladus and Hygrohypnum HYPNACEAE 23
2b. Gametophytic thallus not radially symmetrical, but dorsiventral ; often
conspicuously bilaterally symmetrical [HEPATICAE]
Sa. Thallus flattened, expanded, green above, colorless beneath the
upper layer containing air chambers, these generally opening to
the ventral exterior by pores ; rhizoids of 2 forms, one smooth
and thin-walled, the other internally roughened and thick-
walled.
6a. Plants free-floating, at least at first ; generally less than 1.5
cm. in length; sporophytes embedded in notch of game-
tophyte Ricciocarpus RICCIACEAE 19
6b. Plants not free-floating; usually much longer than 1.5 cm.,
often reaching 10 cm. or more; sporocarps borne on
stalked receptacles Con-
ocephalum and Marchantia MARCHANTIACEAE 19
5b. Thallus either flattened and expanded, or organized into a stem-
like structure bearing 2 or 3 rows of leaf-like organs; green
throughout ; rhizoids always smooth-walled.
7a. Thallus body simple, undulate-margined to somewhat lobed,
more or less dichotomous, sometimes with stomatal slits ;
capsule long, slender, sessile, 2-valved, stomata-bearing
ANTHOCEROTACEAE 22
7b. Thallus body simple, branching pinnately, palmately, or
dichotomously; or consisting of a simple or branching bi-
laterally symmetrical axis bearing 2 lateral rows of gen-
erally overlapping leaf-like organs ; neither air-chambers
nor pores present; capsule stipitate, 4-valved, or rarely
opening irregularly at the apex.
8a. Gametophyte simply thallose, with undulate or ob-
scurely lobed margins, or deeply pinnatifid; capsule
4-valved, or opening irregularly.
9a. Plant body a pinnately-, palmately-, or dicho-
tomously branching thallus ; sporophytes
borne on special short branches
RICCARDIACEAE 20
3
4 AQUATIC PLANTS OF THE PACIFIC NORTHWEST
9b. Plant body varying from a simple thallus to a pinnate arrange-
ment of irregular thallose plates along a central axis; sporo-
phyte arising from the ventral surface of the axis
PELLIACEAE 20
8b. Gametophyte consisting of a simple or branching cylindrical stem-like
structure bearing 2 lateral rows (and often an additional ventral row)
of generally overlapping, thin, bright green, leaf-like organs ; sporo-
phytes borne at the ends of the main axes or their branches; capsule
4-valved.
10a. Leaf-like organs entire, or if lobed, the lobes similar
LOPHOZIACEAE 20
10b. Leaf-like organs 2-lobed, the lobes dissimilar_ SCAPANIACEAE 22
lb. Plants typically differentiated into true roots, true stems, true leaves ; vascular
tissue present ; plants reproducing by spores or seeds.
Ila. Gametophyte and sporophyte independent at maturity ; plants reproduc-
ing by spores [PTERIDOPHYTA]
12a. Plants free-floating; leaves 2-lobed, imbricate ; rootlets and
sporocarps borne in pairs on the under surface
Azolla filiculoides SALVINIACEAE 25
12b. Plants rooting in the subsoil ; not free floating.
13a. Vernation circinate (i.e. leaves coiled in the bud) ; leaf
blades more or less expanded.
14a. Leaves with 4-parted clover-like blades ; or fili-
form, without blades; sporangia in ovoid or
globose sporocarps borne near the leaf bases....
MARSILEACEAE 25
14b. Leaves not clover-like or filiform; sporangia
membranous, clustered on the dorsal surface of
the leaves POLYPODIACEAE 24
13b. Vernation not circinate; leaves various.
15a. Leaf of 2 parts, a sterile portion and a spore-
bearing spike OPHIOGLOSSACEAE 24
15b. Leaf scale-like or quill-like, not in 2 parts.
16a. Stems hollow, jointed; leaves scale-like,
whorled EQUISETACEAE 27
16b. Stems short, not jointed; leaves quill-like,
not whorled ISOETACEAE 28
11b. Gametophyte reduced and dependent upon the sporophyte; plants repro-
ducing by seeds [SPERMATOPHYTA]
17a. Plants normally free-floating or submerged.
18a. Normally free-floating on or immediately beneath the
water surface; plant consisting of a small round, oval,
or oblong, often flattened, undifferentiated thallus
body, rootless or with one to several rootlets dangling
from the lower surface; flowers, when present, almost
microscopic, borne in minute spathes at base of the
thallus LEMNACEAE 84
18b. Not free-floating; normally submerged or largely so,
but rooting in the subsoil ; plant consisting of normal
stem, leaves, and roots; leaves sometimes floating or
raised above the water level.