24 Carats

Weighing about 200 milligrams each, the seeds of a Carob Tree (Ceratonia siliqua) have been used as a unit of mass for hundreds of years, and also became an expression of purity for certain mineral alloys.  Today we use finer measures for gems and minerals, but no jewel could have been more precious than the tree that bore these seeds. Providing shade, lumber, food and fodder, a single carob tree would have been a valuable asset in anyone's territory, especially if it was a female tree.  Carobs are "dioecious," meaning that an individual is either a pollen-bearing "male" or a seedpod-bearing "female."

A large Carob tree in central Phoenix

Carobs were imported from the Mediterranean region as ornamental trees and are common in older neighborhoods of the Phoenix metro area. They bloom during the winter months here, producing long (4-6") catkins with small green "female" flowers that look like tiny elephant trunks. Male flowers are star-shaped with five simple stamens. Both kinds of flowers release a slightly putrid aroma that serves to attract pollinators. In order to produce seedpods, pollinators need to navigate from a male tree to a female tree with a full load of pollen.

Carob pod, female catkin & male catkin

Another name for carob is "locust," a common term for many kinds of trees in the bean family. It was the seed pods of the locust tree, not insects, that are referred to in the Bible as a source of food, also known as St. John's bread:
"….and his meat was locusts and wild honey." Matthew 3:4
"And he would gladly have filled his stomach with the pods that the swine ate…" Luke 15:16

The pods are the source for sweet edible flour that has been concocted into products marketed as a chocolate substitute. But any discerning chocolate gourmand knows that these efforts generally result in nothing resembling chocolate except in color, and is best left to swine.

Carob leaves and catkins