Pl. stemmata. [L., a. Gr. στέμμα garland, f. στέφειν το crown. In Latin chiefly a garland placed on an ancestral image, hence ancestry, pedigree, genealogical tree.
In the 17th c. a supposed literal sense ‘STEM of a tree’ was often wrongly inferred from the sense ‘stem of a family.’]
1. a. Rom. Ant. The recorded genealogy of a family. b. A diagram showing genetic relationships, a genealogical tree.
[1658. Phillips, Stemma, (Greek) the stalk of any herb or flower; also a stock, linage or pedigree.]
1879. Encycl. Brit., X. 144/1. In the case of plebeian families (whose stemmata in no case went farther back than 366 B.C.).
1904. W. Sanday, Crit. Fourth Gosp., viii. (1905), 239. If we were to construct a stemma, and draw lines from each of the authorities to a point x, representing the archetype, the lines would be long [etc.].
2. Zool. A simple eye, or a single facet of the compound eye, in invertebrates.
1826. Kirby & Sp., Entomol., III. 504. A kind of auxiliary eyes with which a large portion of them [sc. insects] are gifted. These Linné, from his regarding them as a kind of coronet, called Stemmata. Ibid., 505. [Swammerdam] ascertained that the stemmata, as well as the compound eyes, were organs of vision.
c. 1865. Wylde’s Circ. Sci., II. 34/1. Similar to the stemmata of some worms are what are called the simple eyes of insects.
1880. F. P. Pascoe, Zool. Classif. (ed. 2), 285. Ocelli or stemmata, simple or supplementary eyes in insects and spiders.
1892. A. B. Griffiths, Physiol. Invertebr., 355. In the Myriapoda … each stemma has its retinal elements … so disposed … that [etc.].
