The Hist are a species of giant spore trees growing in the innermost swamps of Black Marsh. Argonians are known to have deep connections with the Hist, calling themselves "people of the root", and licking the leaking sap of their trunks in religious rites. Others claim the trees are, in fact, a sentient race, more ancient than all the races of man and mer.
 Ancient Trees
The Hist trees of Black Marsh, most say, were the original life forms on Tamriel. The Hist were considered bystanders of the war between the Ehlnofey, but most of their realm was destroyed as the war passed over it. It is believed that the Hist acknowledge Sithis' role as the original creator. It is said that all Hist are connected at the root—they speak to each other and to the An-Xileel. In the Third Era, the Hist used their influence to call Argonians from across the Empire back to Black Marsh. Having foreseen the Oblivion Crisis, the Hist (through the An-Xileel) ordered the Argonians to assault the invading Daedra. The Argonians poured into the Oblivion Gates with such ferocity that Dagon's lieutenants had to close them. This resulted in an astounding victory for the Argonians and led to the collapse of the Empire in Black Marsh as the Argonians turned to the An-Xileel.
 Hist Sap
When the sap of the hist is licked by an Argonian, the tree is capable of communicating with the Argonian through visions. The sap of the Hist tree seems to increase the combat prowess of those who drink it. The Blackwood Company smuggled a Hist tree from Black Marsh to their headquarters in Leyawiin, and extracted the sap to exploit this. However, when consumed by non-Argonian species, the Hist sap had strong hallucinogenic properties that sent them into dangerous bloodlust, though this particular Hist sap was modified to have similar effects on Argonians as well. At the end of the Third Era, a recruit of the Fighters Guild sabotaged the Hist extraction mechanism, destroying the tree in the process.
- The first edition of the Pocket Guide to the Empire mentions the Hist, though its description of them differs dramatically from that given by other sources.