A number of scholars identify rothem as the White Broom Retama raetam, a tough desert shrub found in the Holy Land and Arabia. Earlier, Moldenke (Plants of the Bible. Chronica Botanica. Ronald Press, 1952) contended that rothem refers to a parasitic plant called dog’s club. In the story of Elijah’s flight from Jezebel, the mention of the broom tree in 1 Kings 19:4 provides detail to the image of desolation brought to mind by the word “wilderness” earlier in the verse. The references to rothem in Psalm 120:4 (“. . . with glowing coals of the broom tree”) and Job 30:4 (“. . . and to warm themselves the roots of the broom”) have led scholars to conclude that it is indeed the broom shrub, since it makes a very hot fire, due to the oil in the stems and leaves. The place name Rithmah (“place of rothem”) referred to in Numbers 33:18f. may also refer to the broom. The white broom is found on hills, rocky places, ravines and sandy places throughout the Holy Land, especially near the Dead Sea, in Gilead, on Mount Carmel, in the Syrian desert, and on the Phoenician coast.

The white broom, which is more of a large bush than a shrub, can reach a height of 2 meters (7 feet). It has many small branches, few leaves, and clusters of white flowers that make the shrub a beautiful sight on a hillside.

In 1 Kings 19:4 the New Jerusalem Bible renders rothem as “furze bush,” also known as “gorse,” in an attempt to use a name known to English gardeners, but neither “gorse” nor “furze” are familiar to botanically ignorant city-dwellers of the twenty-first century. Hence, some modern versions use a generic term in 1 Kings, such as “large bush” (Contemporary English Version), “tree” (Good News Bible, and “bush” (New Century Version). In areas where plants are still known by species names, translators can select a shrub that grows in dry, barren areas (assuming it is big enough to offer shade), or transliterate from the Hebrew (rothem) or a major language (for example, retem in Arabic). Otherwise, they can use “small tree” or “shrub.”

In Psalm 120:4 a local kind of wood that produces a very hot fire could be used, since the text is rhetorical, and needs an image of something very hot.

The reference to broom in Job 30:4 poses major textual and exegetical problems, which explains the variety of renderings in modern Bibles. New Revised Standard Version, updated edition reads “they pick mallow and the leaves of bushes, and to warm themselves the roots of the broom.” Good News Bible and the New International Version have these poor folk eating the roots of the broom tree. However, reliable sources tell us that the root of the broom tree is poisonous. That is why Moldenke suggested that it must be another plant, namely the parasite Dog’s Club Cynomorium coccineum, which grows up out of the roots of the broom tree. However, there is good evidence that the writer intended to say the roots were “burned” (as in New Revised Standard Version, updated edition), not “eaten” (as in Good News Bible and New International Version).

Source: Each According to its Kind: Plants and Trees in the Bible (UBS Helps for Translators)

In the Contemporary Chichewa translation (2002/2016) it is translated as “mopane tree .” These trees grow in Southern African countries. They can grow up to 18 meters high and their leaves have a butterfly shape. They’re good for firewood and timber as they are in the category of hardwood trees because they can live for up to 100 years. (Source: Mawu a Mulungu mu Chichewa Chalero Back Translation)