Juniper
JUNIPER (רֹ֫תֶם, H8413, broom[?]). Juniper is mentioned four times, twice in 1 Kings 19:4 (KJV) where Elijah sat down under the Juniper tree; once in Job 30:4, where in the wilderness, Juniper roots were dug up for food; and in Psalm 120:4 “sharp arrows, with coals of Juniper.”
The Heb. word rōtem is similar to the Arab. word retem. The Moorish word retama is given to a kind of Broom, Genista monosperma. (Synonyms— Retama monosperma or Spartium monospermum). Found in Pal. and Syria, it produces big shrubs with white flowers, which give good shade.
The root of this Broom makes excellent charcoal (RSV Ps 120:4). The roots are, however, poisonous. Job’s Juniper was prob. a parasite, Cynomorium proccineum, which grows on the roots of this Broom. It has a fleshy, edible toadstool texture, and because it was popular in Malta, it was called Fungus melitensis.
International Standard Bible Encyclopedia (1915)
This is quite certainly the Arabic ratam (Retama retem, Natural Order, Leguminosae), a variety of broom which is one of the most characteristic shrubs of the deserts of Southern Palestine and southward to Egypt. Though the shade it affords is but scanty, in the absence of other shrubs it is frequently used by desert travelers as a refuge from the sun’s scorching rays (compare 1Ki 19:4). The root yields good charcoal, giving out much heat (Ps 120:4). For people to be reduced to chew it for nourishment betokens the lowest depth of starvation (Job 30:4). Indeed so hopeless is this root as a source of food that many commentators believe that the accepted text is in error, and by altering a single letter, substituting the Hebrew letter, cheth, ("ch") for he ("h"), they get a reading, which has been adopted in the Revised Version margin, "to warm them" instead of "their meat," which certainly is much more probable.