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AN UNDESGRIBED SPECIES OF CETRARIA 
Lincoln W. Riddle 
Several years ago, while working over the material of Cetraria in the Tuck- 
erman lichen collection (in the Crypt ogamic Herbarium of Harvard University), 
I came across specimens of a species of Cetraria which had been named in manu- 
script by Tuckerman, but no description of which had ever been published. 
Subsequently I found specimens from different localities in other herbaria. As 
the species is apparently not uncommon in northwestern America, it seems 
-advisable that an account of it should be published. With the kind permission 
of Professor W. G. Farlow, I present the following description: 
Cetraria pallidula Tuckerman in herb. sp. nov. Thallus foliaceus cartilagin- 
eus rigidus submonophyllus, laciniis latis rotundatisque 10-20 mm. longis, 5-10 
mm. latis, adscendentibus; superne ochraceo-flavus irregulariter rugoso-plicatus 
vel partim lacunoso-reticulatus, sorediis et isidiis destitutus; subtus ochraceo- 
flavus vel paulo pallidior, rhizinis concoloribus parcissime instructus; intus albus. 
Thallus ad marginem cum spermagoniis sparsis tuberculiformibus nigris 
instructus. Apothecia marginalia applanato-cupuliformia, 3-6 mm. lata; disco 
fulvo vel castaneo; margine thallo concolore tenui primum crenato demum 
tuberculato. Sporae decolores simplices globosae, diametro 4-6/*. 
Thallus foliose, cartilaginous, rigid, submonophyllous; lobes broad and 
rounded, 10-20 mm. long and 5-10 mm. wide, irregularly rugose- wrinkled, or 
partly somewhat lacunose-reticulate, without soredia or isidia; yellow-ochraceous 
above, and the same color or slightly paler beneath, with occasional scattered 
concolorous rhizoids; medulla white. Upper cortex 28-35/* thick, chondroid, 
the cells with lumina about 3/* in diameter and much thickened walls; lower 
cortex 15-18/* thick, similar in structure to the upper cortex, but less chondroid. 
Spermogonia in scattered, submarginal, black tubercles, not numerous. Apo- 
thecia marginal, 3-6 mm. in diameter, concave; disk fulvous to chestnut; margin 
ochraceous, thin, at first crenate, soon becoming tuberculate; hymenium 45-50 /* 
high, subtended by a colorless chondroid hypothecium 50-60/* high; spores color- 
less, simple, globular, 4-6/* in diameter. Type-specimen: “near Mt. Adams, 
Washington Territory, legit C. G. Pringle 1881” in the Tuckerman Herbarium. 
The species is represented by two specimens in the Herbarium of Wellesley 
College, one from Falcon Valley, Washington, collected by C. G. Pringle, 7 
Sept., 1881; the other from Mt. Hood, Oregon, collected by Mrs. Dorchester, 
August, 1890. The plant was also collected by Mr. R. S. Williams (No. 17) at 
Lake Lindeman in the Yukon Region, 24 April, 1898, and recorded by Dr. R. 
H. Howe, Jr., in the Bulletin of the Torrey Botanical Club 38 : 292 (191 1) under 
the name Cetraria Oakesiana Tuck., with the note “this plant represents a new 
variety, a name for which is about to be published; reference will be made to 
this record at the time of publication.” In regard to the note quoted it should 
be said that contrary to my expectation at the time that Dr. Howe sent me the 
material for determination, circumstances have delayed the publication of this 
description until the present. 
