Download PDF

680 University of California Publications in Botany V° L - S
L
3. Fucus edentatus f. costatus Gardner
Fronds slender, subcoriaceous, 15-25 cm. high, regularly dicho-
tomous, yellowish brown, segments distinctly linear, relatively long,
reduced in width above each forking, widest 5-8 mm., terminal 2-4
mm., midrib highly developed, percurrent, alae narrow and mem-
branaceous, cryptostomata sparse, prominent; receptacles definitely
delimited, simply or mostly bifid, 20-35 cm. long, apices acute; con-
ceptacles moderately abundant and conspicuous.
Growing on rocks in the lower third of the littoral belt. Lower
Puget Sound region, Washington.
Gardner, Genus Fucus, 1922, p. 30, pis. 23, 24. Fucus evanescens
f. august us, Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc),
no. 926; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 284.
The plants distributed in the Phycotheca Boreali-Americana as
no. 926 are from the type locality, but were taken from the upper
limit of the belt of distribution when the tide was well in ; they are
considerably battered and worn away, and thus cannot be said to be
in typical condition.
This form resembles closely F. evanescens f. angustus Kjellm. in
width of fronds, and was so referred as is cited above. Subsequent
to the foregoing publications, material of the species, collected and
determined by Kjellman on the Vega expedition, has been received at
the Herbarium of the University of California (no. 132699). The lack
of a prominent percurrent midrib, almost complete absence of crypto-
stomata, and especially the very small receptacles of Kjellman 's
material, indicate unmistakably that our plant is of a different lineage.
4. Fucus edentatus f. acutus Gardner
Fronds 9-15 cm. high, arising from a relatively broad, flat hold-
fast, dichotomous, angles acute, olive green, black on drying ;
segments
linear, 3-4 mm. wide, apices truncate, midrib very prominent, percur-
rent, alae relatively narrow, persistent, cryptostomata sparse; recep-
tacles single or deeply bifurcate, tapering at both ends, 2-2.5 cm. long.
Growing on sandstone in the middle littoral belt. Bellingham
( Fairhaven ) ,
Washington.
Gardner, Genus Fucus, 1922 p. 31, pi. 25. Fucus inflatus f.
linearis, Setchell and Gardner, Alg. N.W. Amer., 1903, p. 280.
The very dark color on drying, the absence of caecostomata, and
the sparseness of cryptostomata in this form seem amply sufficient to