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1925] Setchell-Gardner: Melamophyceae 595
Key to the Species
1. Blade entire or slightly split at the outer end 2
1. Blade split more or less deeply into several narrow segments 8
2. Fronds, except when young, arising from creeping "rhizomes" 3
2. Fronds without creeping "rhizomes" 4
3. Mucilage ducts absent from stipe 3. L. longipes (p. 597)
3. Mucilage ducts present in both stipe and blade 4. L. Sinclairii (p. 598)
4. Holdfast a solid parenchymatous disk 6. L. personata (p. 599)
4. Holdfast of branched hapteres 5
5. Blade densely bullate all over 5. L. Farlowii (p. 599)
5. Bullae in two rows within the margin or scattered 6
6. Stipe long, complanate, except at base, very dark brown
2. L. complanata (p. 596)
6. Stipe short, terete, color yellowish brown 7
7. Mucilage ducts in the blade only 1. L. saccharina (p. 595)
7. Mucilage ducts in both blade and stipe 7. L. cuneifolia (p. 600)
5. Holdfast a solid parenchymatous disk 8. L. ephemera (p. 603)
8. Holdfast composed of stout branched hapteres 9
9. Fronds plane, stipe long, up to 1 m 10
9. Fronds more or less bullate, stipe relatively short 7. L. cuneifolia (p. 600)
10. Stipe cylindrical to near apex 11
10. Stipe compressed from just above holdfast 11. L. platymeris (p. 605)
11. Mucilage ducts of stipe in a circle just beneath the cortex, stipe slender
9. L. dentigera (p. 604)
11. Mucilage ducts of stipe deep seated, stipe rigid 10. L. Andersonii (p. 605)
1. Laminaria saccharina (L.) Lamour.
Holdfast of numerous, branching, more or less rigid hapteres often
extending for 5-8 cm. up the stipe which is very variable in length,
from 5-50 cm., cylindrical, flattening above into the blade, 6-9 mm.
diam., without mucilage ducts ; blade undivided, usually coriaceous or
membranaceous when growing in quiet waters, plane, undulate, or
with two distinct rows of large bullae along the margin, ovate to ovate-
lanceolate, often with cuneate base, with mucilage ducts; color rich
brown.
Growing on rocks in the upper sublittoral belt. Reported from
various localities from the Alaskan peninsula to Coos Bay, central
coast of Oregon.
Lamouroux, Essai, 1813, p. 22; Setchell and Gardner, Alg. N.W.
Amer., 1903, p. 261 ; Setchell, Kelps of the U. S. and Alaska, 1912a,
p. 149. Fucus saccharmus Linnaeus, Sp. PI., 1753, p. 1161.
All attempts to separate this widespread species of the cooler waters
of the northern hemisphere have been unsatisfactory. The type has
been assumed to be the plant with mucilage ducts in the blade, but
lacking them in the stipe. This seems to be a condition with all the