VI. Rhodymeniales. 
Fam. 16. Rhodymeniacez. 
1. Rhodymenia palmata (L.) Grey. 
Greville, Algæ Brit. 1830, p. 93; Harvey, Phye. Brit. II, pl. 217 (1849); J. Agardh, Sp. g. 0. Vol. Il pars 
II (1852) p. 376; Thuret, Rech. s. la fécond. des Fucacées etc. Seconde partie. Ann. sc. nat. 4° sér. 
tome 3, 1855, p. 43, pl. 3, figs. 8, 9. Wille, Morph. og phys. Stud. over Alger. Nyt Mag. f. Naturvid., 
Bd. 33, II, 1891, p. 99. Buffham 1893, p. 294, Pl. 13, figs. 13, 14; V. M. Grubb, Prelim. Note on 
the reprod. of Rhodym. palm. Annals of Botany, Vol. 37, No 145, 1923; E. M. Delf and V. M. 
Grubb, The spermatia of Rhodymenia palmata, Ag. Ann. of Botany, Vol. 38, No. 150, 1924; Ch. 
Killian, Le développement morphol. et anatom. du “Rhodym. palm”. Annales d. sc. nat. 10° ser. 
t. 8, 1926; Printz, Algenveg. d. Trondhjemsfjordes 1926, p. 72; M. A. Westbrook, Contrib. to the 
cytology of tetrasp. plants of Rhod. palm. Ann. of Bot., Vol. 42, No. 165. 1928. 
Fucus palmatus L. Spec. plant. II, p. 1162 (1753). 
Fucus bullatus O. Fr. Miller, Flora Danica, tab. 770, 1778. 
Fucus caprinus M. Vahl, Flora Danica, tab. 1128, 1794. 
Fucus delicatulus M. Vahl, Flora Danica, tab. 1190, 1797. 
Spherococcus palmatus Kützing, Phyc. gener. 1843, p. 409. Taf. 63 I, Tab. phyc. 18, Tab. 89, 90. 
The frond springs from an orbicular attachment disc, but a smaller or greater 
number of fronds, besides the primary one, may issue from the same disc, though 
usually of a smaller size. An attachment disc more than 1 cm in diameter showed 
in the centre the remains of the decayed primary shoot, 
near it three fronds produced later, and at the border a | | Gy a) 
great number of small, feebly developed fronds. The frond | EN Ns BZ 
of the first year has a short cylindrical stipe which is N) | ZEN 
flattened upwards into the wedge-shaped base of the flat \ | || 
frond. This may be undivided or more or less cleft at the 1 | LATE 
top, the first is very often the case in the Danish waters. A B C DEZE 
Young plants are found in summer, e.g. on the stipes or Fig. 564. 
> 5 2 50 Rhodymenia  palmata Young 
the laminæ of Laminaria digitala and L. hyperborea, and „jants growing on the frond of 
are easily recognisable by their structure. They must have Laminaria digitata, August. Nat 
arisen by germination of tetraspores produced in winter. Fa 
The development of the young plants has been described by Kırrıan (1926) on the 
basis of material from the above-named substratum. The growth of the frond stops at 
the end of summer. In specimens from greater depths and from the inner waters 
D.K.D. Vidensk. selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII.4. id 
