Platoma tenuis M.Howe & W.R.Taylor

• Region

  South America

• Country

  Brazil

• Locality

  Cabo Frio

• Coordinates

  -22.8747, -42.0321

• Coordinate Uncertainty (m)

  8756.57

• Georeferencing Method

  Georeferencing Quick Reference Guide, Version 2012. Georeferenced to the approximate geographic center of the city of Cabo Frio in Mun. Cabo Frio, Rio de Janeiro, Brazil. Used Google Maps - Map and Earth Views to locate Cabo Frio. Used the Google Maps – What's Here Tool to find the coordinates of the approximate geographic center of the city (extending the city limits to include portions excluded by Google Maps based on the location of the Cabo Frio airport (Aeroporto Internacional de Cabo Frio) and other entities located in Cabo Frio but not included in the bounds of the city, see: http://wikimapia.org/#lang=en&lat=-22.890000&lon=-42.040000&z=13&m=b&show=/29849852/pt/Salinas-da-C-N-A-&search=cabo%20frio%20rio%20de%20janeiro, accessed: 8/25/2015). Used the Google Maps – Measure Distance Tool to find the linear extent by measuring from the selected coordinates to the farthest extent of Cabo Frio (at: -22.930044, -42.092845). Input coordinates, coordinate precision (.00001 degrees), coordinate source (locality description), datum (WGS84), linear extent (8750.0 m), and measurement error (5 m) into the MaNIS Georeferencing Calculator to find the uncertainty radius (according to Georeferencing Quick Reference Guide, Named Place: Defined Area).

• Geodetic Datum

  WGS84

• Distribution

  Map all specimens of this taxon

cm

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6 7 8 9 10
copyright reserved

The New York
Botanical Garden

Platoma tenuis Howe & Taylor, sp. nov.

Thallo subsessili, plana, maxime molli et gelatinosa, tenui, 60-90 [j
crassa (imperfecte madefacta), prope orbiculari vel subreniformi, 1.5-
6.5 cm. longo aut lato, subintegro vel parce et plus minusve
convenienter lobato, aliquando minute undulato-crenulato, purpureo-
vinaceo, superficie baud nitente, saepe (sicco) sub lente scrobiculato-
reticulata; medulla frondis aliquantum dense filamentosa, filis homo-
geneis, maximam partem 0.5-3 |j diam. (protoplastis solis) ; strato
corticali laxo, filis dicliotomo-fastigiatis, plerumque ter vel quater
furcatis, cellulis (protoplastis) plerumque obovoideis vel pyriformibus,
superficialibus 3-5 [j altis (longis), intimis 6-10 p longis; cystocarpiis
immersis, minutis, circa 50 ¡j diam., nudis vel paucis filis iuvolucratis
instructis.

Ad oras Brasiliae (Cabo Frio, Exped. Hassleriana).

Species fortasse P. cyclocolpae (Mont.) Sclimitz proxima, sed
tliallus planior et integrior est.

Thallo subsessili, plana, maxime molli et gelatinosa, tenui 60-90 |j
thick (when imperfectly soaked out), nearly orbicular or subreniform,
1.5-6.5 cm. long or wide, subentire, or sparingly and more or less con-
formably lobed, here and there minutely undulate-crenulate, the sur-
face dull, often scrobiculate-reticulate under a lens after drying;
color (dried) purplish-vinaceous19 or vinaceous; medulla of frond
rather compactly filamentous, its filaments homogeneous, mostly 0.5-
3 [j in diameter (protoplasts only), the rather loose cortex of
dichotomo-fastigiate filaments, these mostly three or four times forked,
their cells (protoplasts) usually obovoid or pyriform, the superficial
commonly 3-5 [j high, the inner 6-10 ¡j in long diameter; cystocarps
imbedded, minute, about 50 p in diameter, naked, or with a few
18 Homonym of Halymenia ulvoidea (Sond.) Kiitz.

!9 Ridgway, op. cit. pis. 39, 27.

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1. Platoma tenuis, cortical filaments, x 615.

	mm	1
		

1, 1

Howe and Taylor: Brazilian algae

33

peripheral filaments suggesting a very rudimentary pericarp. (Fig.
15b; pi. 2, fig. 1.)

Dredged, Cabo Frio, Hassler Expedition 1043g and 1043g', ap-
parently associated with Halymenia rosea and H. vinacea. Type, the
larger specimen (1043g).

Platoma tenuis has a vegetative structure closely resembling that
of Bermuda plants currently referred to Platoma cyclocolpa (Mont.)
Schmitz. The thallus is, however, more distended and plane and
more nearly entire than in that, or, we believe, in any other species
previously referred to the genus Platoma.

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