Collema nigrescens - Common Macrolichens of the Pacific Northwest

< Collema furfuraceum

Dermatocarpon deminuens >

Click on Characteristic name for explanation. Click on image for larger version.

Collema nigrescens

Overview
PNW Range:
West side	Uncommon
East side	None
Immediate coast	None
Alpine or subalpine	None
Habitat:	Low-elevation hardwood forests and savanna.
Substrate:	Bark of broad-leaved trees and shrubs.
Comments:	Collema curtisporum is similar but differs in spore size and septation.
Synonymy:	none

Collema nigrescens - Apothecia

Apothecia
by B. McCune

1/4

Collema nigrescens - Spores

Spores
by B. McCune

2/4

Collema nigrescens - Apothecia

Apothecia
by B. McCune

3/4

Collema nigrescens - Habit

Habit
by B. McCune

4/4

❮ ❯

Scale: Bar=1mm unless noted

Growth Form
Fruticose:	Never
Foliose:	Almost always
Crustose:	Never
Appressed Foliose:	Almost always
Fluffy Foliose or Strappy:	Never
Dangling Hair:	Never
Erect Hair:	Never
Appressed Hair:	Never
Stalks With Squamules:	Never
Stalks:	Never
Squamules:	Never
Single Holdfast:	Never
Dangling Nets:	Never
Lobe Width (mm):	7.5 (± 1.5)

Upper Surface
Upper Surface Color (Dry)
Dark Gray:	Rarely
Black:	Almost always
Olive Black:	Sometimes
Upper Surface Tomentose:	Never
Upper Surface Pruinose or Scabrid:	Never
Upper Surface with Network of Ridges:	Never
Upper Surface with Pseudocyphellae:	Never
Upper Surface with Holes into Cavity:	Never
Cilia on Margins:	Never

Lower Surface (Foliose)
Lower Surface Color (Dry)
Dark Gray:	Rarely
Black:	Almost always
Veined Below:	Never
Rhizinate Below:	Never
Tomentose Below:	Never
Cyphellae:	Never
Pseudocyphellae Below:	Never
Papillae Below:	Never

Interior
Inside (Medulla) Yellow or Orange:	Never
Central Cord:	Never
Hollow Stalks or Hollow Lobes:	Never
Gelatinous:	Almost always

Photobiont
Green Algae Primary Photobiont:	Never
Cyanobacteria Primary Photobiont:	Almost always
Internal Cephalodia:	Never
External Cephalodia:	Never

Sexual Reproduction
Perithecia:	Never
Apothecia:	Almost always
Mazaedium:	Never
Disk Color (Dry)
Disk Brown or Tan:	Almost always

Asexual Reproduction
Isidia:	Sometimes
Soredia:	Never
Lobules:	Never