A Grammatical Dictionary of Botanical Latin

thel-, thele-, thelo-; -thelium,-ii (s.n.II): in Gk. comp., nipple- [> Gk. thElE (s.f.I), papilla, mammilla, nipple; ‘the part of the breast which gives suck, the teat, nipple; papilla]; see nipple; see breast; see tuberculum,-i (s.n.II); cf. epithelium;

- thelecarpus, with a nipple-like fruit; thelephorus, bearing nipple-like projections; thelespermus, with seeds having nipple-like projections (Stearn).

- thelotremoideus,-a,-um (adj.A), “having tubercular double-walled apothecia like those of Thelotrema of the lichens” (Snell & Dick).

Taxithelium, a genus of mosses, "So named because of several papillae [i.e. nipples] arranged in a row [Gk. -taxis,-is, arrangement, order] over the cell lumen" (Crum & Anderson 1981).

Thelebolus, “from ‘thele,’ a nipple, and ‘boleo,’ to eject. Lycoperdaceae” (Paxton).

Thelephora, “from ‘thele,’ a nipple, and ‘phoreo,’ to bear; in allusion to the papillose surface of all the species. Agaricaceae” (Paxton).

Thelesperma,-atis (s.n.III), “From the Greek thele, a nipple, and sperma, seed, on account of the papillose achenes” (Fernald 1950), according to Stearn (1996) “in allusion to the form of the seeds (cypselae) in some species.”

Thelia, a genus of pleurocarpous mosses with conspicuous high, curved papillae on the leaf cells.

Thelocactus from Gk. Thele, nipple and Cactus, old genus name, in reference to the tubercle shape (FNA). Thelotrema,-atis (s.n.III): from thele, a nipple, and trema, orifice; the protuberances of the thallus are perforated. Graphidaceae (Paxton) Note: a thelion [thelium,-ii (s.n.II), abl. sg. thelio; or thelion,-ii (s.n.II), abl. sg. thelio] is “the central point of the nipple” (WIII). Epithelium (Eng.noun): Epi-thelium: coined by F. Ruysch. “referring to the red part of the lip (prolabium), he says, ‘I cannot call this ‘epidermis,’ seeing that the subjacent tissue is not skin, but a different substratum covered with sensitive (nervous) papillae, which are finely injected red.’ He than goes on to say that, as the cuticle lies on papillae, he will call it Epithelida or Epithelia, from ‘epi,’ upon and ‘thElE, ‘papilla’ or ‘mammilla,’ and he adds that for the same reason he calls the inside coating of the cheeks by the same name.” – Ruysch, F. Thesaurus Anatomicus, III. No. xxiii. P. 16.

Thelium,-ii (s.n.II): arbitrarily “a layer or layers of cells.” Epithelium is then considered as the ‘thelium’ of free surfaces, and endo-thelium as the ‘thelium; of internal closed spaces. The latter has also been termed pseudo-epithellium, to distinguish it from the real epithelium of mucous membranes” Ruysch, F. Thesaurus Anatomicus, III. No. xxiii. P. 16.