Rhodochorton obscurum K.M.Drew

• Region

  North America

• Country

  United States of America

• State/Province

  California

• County/Municipio

  San Mateo Co.

• City/Township

  Pillar Point

• Coordinates

  37.4988, -122.498

• Coordinate Uncertainty (m)

  602

• Georeferencing Method

  GEOLocate Web Application. Used the GEOLocate Web Application to georeference to the city center.

• Geodetic Datum

  WGS84

• Distribution

  Map all specimens of this taxon

NEW YORK BOTANICAL GARDEN

NEW YORK

00900661	botanical

ALGAE DISTRIBUTED FROM THE	GARDEN

HERBARIUM OF THE UNIVERSITY OF CALIFORNIA

NEW YORK
BOTANICAL
GARDEN

289. Rhodochorton obscurum Drew

Pillar Point, San Mateo County, California.
Co-type.

N. L. Gardner, No. 4229. May, 1918.

J-SOTYPE OF:

Uajw. u*.	i.4-(j^Y

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200 UJ

Algae distributed from the Herbarium of the
University of California

Rhodochorton obscurum Drew
Carmel Bay, Monterey Co., Calif.
May 1915

N. L. Gardner. No, B958a

Rhodochorton obscurum sp. nov.

Pig. 87. Transverse section of the stipe of Laminaria Sinclairii with
antheridial (?) and tetrasporic plants growing side by side. Note the single
parietal chromatophore without a pyrenoid. X 1600.

NEW YORK
BOTA NICAL
GARDEN

Rhodochorton obscurum Drew, sp. nov.

Univ.Calif.Pubi.Bot.l4|193.pi.48.f.87.4 F 1928.

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Plants endophytic; whole plant unbranched, consisting
of a lower, endophytic portion, penetrating between and
through the cells of the host to a depth of 1-4 layers
(occasionally more) and an upper free portion of about five
cells; cells cylindrical, increasing in diameter but decreas-
ing in length from the base of the free portion to the apex;

5.0-6.0 y by 9.0-11.0 ]i at the base, 9.0 p. by 6.0-7.5 ]i at
the apex; chromatophore parietal, pyrenoid absent; two kinds
of sporangia present on distinct individuals; tetrasporangia
terminal on the main axis, subglobular, 10.0-13.0 V1 by 13.0-
18.0 p, cruciately divided; antheridia ? terminal and lateral
on the main axis and the short branohlets, 3.5-4.5 u by 5.5-
6.5 ji.

Forming dark red, velvety expansions on the stipe of
laminaria Sinclairii. Port Point, San Francisco; Duxbury
Reef, Marin Oounty; Pillar Point, San Mateo County, California.
February, March, April, May. Type, Herb. Univ.Calif, no.294548
(Gardner, no. 4229).

A knowledge of the method of germination would help con-
siderably toward a complete understanding of the endophytic
system of this species. Attempts to separate the endophytic
system of filaments from the host by means of treatment with
potassium hydroxide were not successful as the species is
intracellular. In sections, the free filaments seem to be
continued directly downward with no lateral connections with
the neighboring filaments. This suggests that the germinating
spore grows in both directions, one filament growing into the
host and the other, the spore-bearing filament, in the other