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636 University of California Publications in Botany [Vol. 8
No genus of the Laminariaceae, not even excepting the genus
Lamimaria, is so confusing as to specific segregation within its limits
as Alaria. Ruprecht, J. G. Agardh, Kjellman, Setchell, and Lendo
have struggled with it and assisted both in clearing some species and
confusing others. The arrangement of our species by Setchell (1912a)
and the monograph of the genus by Yendo (1919) are followed in their
essentials in our account. We cannot, however, follow Yendo in all
his distinctions since our experience leads us to assign somewhat
different degrees of importance to certain of the characters which he
stresses. We are not able to apply the distinction into "Holosoria"
and "Metasoria" Avith such precision even as Yendo (1919, pp. 24—26)
indicates as possible.
Key to the Species
1. Midrib solid throughout 2
1. Midrib fistulose at intervals 9. A. fistulosa (p. 644)
2. Sporophylls short 3
2. Sporophylls long 7
3. Sporophylls narrow 4
3. Sporophylls broad 5
4. Blade long and broad above 2. A. praelonga (p. 637)
4. Blade short and narrow 1. A. nana (p. 636)
5. Stipe long, very much flattened 3. A. tenuifolia (p. 638)
5. Stipe short, cylindrical 6
6. Midrib broad 4. A. marginata (p. 640)
6. Midrib narrow 5. A. Pylaii (p. 641)
7. Sporophylls narrow 8
7. Sporophylls broad 8. A. valida (p. 643)
8. Cross-section of midrib elliptical 6. A. dolichorhachis (p. 642)
8. Cross-section of midrib oblong 7. A. lanceolata (p. 642)
1. Alaria nana Schrader
Plants anchored by firm strong hapteres; stipe 4.5-7 cm. long,
robust, 5-8 mm. diam., terete; rhachis 2-4 cm. long, slightly com-
pressed, passing gradually into the midrib ; blade usually widest near
the base tapering rather abruptly below and gradually above, with
some specimens nearly linear, 40-60 cm. long, 3-8 cm. wide ; midrib
prominent, 4-6 mm. wide, nearly rectangular in cross-section ; sporo-
phylls 25-50 in number, linear to slightly elliptical, 6-12 cm. long,
8-15 mm. wide, rounded at the outer end, tapering rather abruptly at
the base to a distinct short stipe, sori covering both entire surfaces.
Growing on rocks in the upper part of the littoral belt, in localities
exposed to the action of the heavy surf, in company with Postelsia
palmaeformis and Lessoniopsis littoraiis. Port Renfrew, Vancouver
Island, British Columbia.