armillatus
Bands of veil remnants on the stalk, having a bracelet

arorae
David Arora, American mycologist

arquatus
Arched

Arrhenia, arrhenii
Pertaining to male

arrhizus
Without a root

artesiana
Water flows up like a faucet (possibly referring to its shape)

arvalis
Of the fields

arvensis
Growing in fields

arvernense, arvernensis
The Arverne region in France

arvinaceus
Greasy

Ascobolus
Bladder thrower

Ascocoryne
Club bladder

Ascotremella
Trembling bladder

asema
Without sign

aseroe
Disgusting

aseroiformis
Formed disgustingly

asper, aspera
Rough

asperula
Slightly rough

aspidelllus
Small shield

aspideoides
Resembling aspideus

aspideus
Like a rough shield

asprata
Richly gilded

asprella
Somewhat rough

assimilata
From assimilate

Asterophora
Bearing stars, star spore

asterophora, asterophorus
Star bearer

asterophoroides
Resembling asterophorus

asterospernum
Star seed

asterospora, asterosporus
Star spores

astraeicola
Living on Astraeus

Astraeus
Pertaining to a star

astragalina, astragalinus
Pertaining to a gold-finch

ater
Black

atkinsoniana, atkinsonianus
George Francis Atkinson (1854-1918), American mycologist

atkinsonii
George Francis Atkinson (1854-1918), American mycologist

atlanticus
Pertaining to the Titan Atlas

atomata
Sprinkled with particles

atra
Black

atramentarius
Inky

atramentosis
Inky condition