All the same species!

These mushrooms are blackening waxcaps Hygrocybe conica which, as they develop, may be red, orange or yellow in colour. However, as soon as they are mature they turn jet black all over, and in that state they may remain standing for several weeks, often in large groups.
The genus Hygrocybe is so named because fungi in this group are always very moist; Hygrocybe meaning 'watery head'. The species have sharply conical caps, reminiscent of a witch's hat, and unsurprisingly the specific epithet conica simply means conical. So, we are dealing with the 'conical, watery headed fungus'!