A Grammatical Dictionary of Botanical Latin

-eus,-a,-um (adj.A):

English adj. suffix: -eous > L. -eus,-a,-um (adj.A), composed of, of the nature of or resembling (a specified substance): L. eus, akin to Gk. -eos, ‘composed of’ (WIII).

1. in L. comp. "indicates material or color or resemblance in quality, [pertaining to, -like, resembling]; noun base; e.g. melleus, pertaining to honey (from mel, honey), purpureus, purple (from purpura, the mollusc yielding a purple dye" see Ch. XVIII "This should not be confused with the Greek -eus meaning 'belonging to' or 'noted for,' e.g. giganteus, belonging to the giants, hence gigantic" (Stearn); adjective suffix “formed from nouns usually to denote material (charteus,ligneus)” (Glare).

e.g. charteus, made of paper (charta,-ae (s.f.I), paper, a leaf of papyrus); ferreus, made of iron (ferrum,-i (s.n.II), iron); floreus, made of flowers (flos,-oris (s.m.III), a flower; ligneus, made of wood (lignum,-i (s.n.II), wood).

Bartholomaeus Ambrosinus (1588–1657).

tegmineus,-a,-um (adj.A): serving as or pertaining to a cover or covering, serving as a shelter, protection, skin, veil [> L. tegmen,-inis (s.n.III), q.v., outer skin, covering];

Ceratodon purpureus (moss): purple-colored, from the Latin adjective purpureus, from the Latin noun purpura, a mollusc generating a purple dye and the Latin suffix -eus, ‘pertaining to the purpura’. The classical Latin adjective purpureus included every manner of reds, violets, brownish or blackish colors, 'dull red with a slight dash of blue' according to the English botanist John Lindley. Bridel ascribed various red shades to the plant parts, reddish branchlets, the costa purple, the lower part rubellus, the upper green; the seta a beautiful purple-red with yellow tints, the capsule rufous, the peristome teeth deep purple at the base, the calyptra grayish-purplish.

Geheebia gigantea (moss): gigantic, monstrous, belonging to the giants, from the Latin noun Gigas, Gigantis, plural: the Gigantes or Giants + the Latin suffix -eus, resembling, pertaining to, referring to a plant of unusual size: this species forms large tufts and can be as tall as 15 cm.

Rhodobryum roseum (moss): roseous; from the Latin adjective roseus, from the Latin noun rosa, a rose + the Latin adjective suffix -eus, resembling the rose.

Rhytidiadelphus loreus (moss):made of thongs or strips, from the Latin adjective loreus, of thongs, made of thongs, from the Latin noun lorum, a thong, a whip, a narrow strap + the Latin adjective suffix -eus, resembling or made of thongs; in reference to the leaves with a stretched whip-like appearance from the long, slender, channeled acumen abruptly narrowed from a sheathing oblong-ovate base.

Sciuro-hypnum populeum (moss): belonging to poplars; from the Latin adjective populeus, of or belonging to poplar trees (species of the genus Populus) from the Latin noun populus, the poplar-tree + the Latin adjective suffix -eus, pertaining to the poplar-tree; described by Hedwig from a specimen collected by Olof Swartz in Sweden on the trunks of Populus tremula (European aspen) and P. alba (the European white poplar).

Straminergon stramineum (moss): straw-colored; from the Latin adjective stramineus, made or composed of straw, straw-colored, a dull yellow mixed with white, from the noun stramen, straminis, straw + tjhe Latin adjective suffix -eus, resembling straw; originally Hypnum stramineum, “coloris straminei,” of the color of straw.

2. -eus,-a,-um (adj.A): in Gk. comp. “indicates ‘possessed by’ or ‘belonging to’ or ‘noted for;’ noun base, usually the name of a person [or proper noun]; e.g. giganteus, huge (from gigas, giant)” (Stearn);

NOTE: Gk.-ei- becomes -e- in Latin: -eios,-a,-on > -eus,-a,-um.

Greek Γιγάντειος,-ά,-ον (gigánteios), gigantic; Latin giganteus,-a,-um (adj.A): “of or belonging to the giants; gigantic” i.e. monstrous (Lewis & Short).

Antitrichia gigantea; moss (belonging to the giants: from the Gk. noun Γίγας, Γῐ́γᾰντος (Gigas, Gigantos), a giant, one of the Gigantes or giants, a Titan + the adj. suffix -eus, belonging to; in reference to a plant of an unusually (gigantic) size for the genus.

Greek Γοργόνειος,-ά,-ον (gorgoneios), pertaining to a Gorgon, of the Gorgons; Latin gorgoneus,-a,-um (adj.A), “of or belonging to the Gorgon [> Greek Γοργώ = Lat. Gorgo,-onis; or Gogona,-ae (s.f.I)].

- endocarpeus,-a,-um (adj.A): of or belonging to the lichen genus Endocarpon.

- [lichen] gelatina hymenea iodo eximie coerulescens, at in apotheciis junioribus, adhuc endocarpeis, ea non tingitur (Nyl.), hymenial gelatin in iodine exceedingly blue, but in younger apothecia, thus far endocarpeous [i.e. a feature of the genus Endocarpon], this [i.e. gelatin] is not stained.

- hymeneus,-a,-um (adj.A): hymeneous, hymenial, of a membrane or thin skin [> Gk. hymen,-enos (s.m.III), a thin skin or membrane, the membrana nictitans of birds; see hymen,-enis (s.m.III).

- [lichen] gelatina hymenea iodo non colorata (nec substantia gelatinoidea thalli) (Nyl.), the hymeneous gelatin in iodine not colored (nor the gelatinoid matter of the thallus).

Orthothecium chryseon; moss] from the Greek adjective χρῡ́σεος (chryseos), golden yellow, golden (Latin chryseus, gold-colored), from the Greek noun χρῡσός (chrysos), gold + the Greek adjective suffix: -eios,-a,-on (Latinized -eus,-a,-um), pertaining to gold.