The Plant Men are a fictitious species existing in the Valley Dor region on the planet Barsoom

Barsoom

Barsoom is a fictional representation of the planet Mars created by American pulp fiction author Edgar Rice Burroughs, who wrote close to 100 action adventure stories in various genres in the first half of the 20th century, and is now best known as the creator of the character Tarzan...

 (i.e. Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

) in the John Carter

John Carter (character)

John Carter is a fictional character, created by Edgar Rice Burroughs, who appears in the Barsoom series of novels. Though actually a Virginian from Earth and a visitor to Mars, he is often referred to as "John Carter of Mars" in reference to the general setting in which his deeds are recorded, in...

 series of books by Edgar Rice Burroughs

Edgar Rice Burroughs

Edgar Rice Burroughs was an American author, best known for his creation of the jungle hero Tarzan and the heroic Mars adventurer John Carter, although he produced works in many genres.-Biography:...

. Ten to twelve feet tall, with short arms resembling an elephant

Elephant

Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...

's trunk, they are hairless except for their head and blue in color except for a broad band of white encircling a single protruding eye; the pupil

Pupil

The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...

 and iris

Iris (anatomy)

The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...

 of which are dead white like the eyeball. The body, legs and feet are humanoid

Humanoid

A humanoid is something that has an appearance resembling a human being. The term first appeared in 1912 to refer to fossils which were morphologically similar to, but not identical with, those of the human skeleton. Although this usage was common in the sciences for much of the 20th century, it...

, but monstrously proportioned, the feet being fully one meter long, and very flat and broad. They possess a massive tail about six feet long, round where it meets the body and tapering to a flat, thin blade at the end, carried at right angles to the ground.
The head, except for the blank face, is covered by a tangle of jet-black hair eight to ten inches in length with each hair the thickness of a large earthworm

Earthworm

Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

. There is no mouth in the face, and the nose is merely a ragged, gaping, inflamed circular hole in the center of the face, similar to an open wound.
The Plant Men have a mouth in the palm of each hand, with which they feed on tender vegetation which they shear with their razor-sharp talons, or the blood of their victims. After "the defiling blood of life has been drawn" from a human by the Plant Men, the flesh may be eaten by the Holy Therns, another Barsoomian race.