A Grammatical Dictionary of Botanical Latin

Rhizoid, an attaching filament; (in mosses) with simple or branched filaments attaching the plant to the substrate; “a hair, frequently branched, serving as a root in Mosses and Hepaticae, not morphologically distinct from the protonema, the same as Rhizine” (Jackson); (in bryophytes) “hair-like structures that function in absorption and anchorage; in liverworts and hornworts one-celled and usually hyaline; in mosses usually brown to reddish, simple or branched, multicellular filaments, generally with oblique end-walls (see tomentum)” (Magill 1990): (in fungi) “a root-like structure; any filamentous, branched, extension of a chytrid thallus acting as a feeding organ; cf. haustorium and holdfast” (Ainsworth & Bisby), “When a host first contracts chitridiomycosis, spores penetrate the skin and attach themselves using microtubule roots,” see chitrid: “rhizoideum (s.n.II), gen. sing. rhizoidei, abl. sing. rhizoideo, nom. & acc. pl. rhizoidea, gen. pl. rhizoideorum, dat. & abl. pl. rhizoideis; cf. radicle;

- rhizoidea plerumque e base amphigastrii atque basem versus folii ventralis et sparse in superficie caulina ventrali exorientia, rhizoids generally arising from the base of the underleaf and also toward the base of the ventral leaf and sparsely on the ventral stem surface.

- rhizoidea ex cellulis amphigastrii orientia, nunquam ex cellulis caulinis, rhizoids arising from the cells of the underleaves, never from cauline cells.

- rhizoidea adsparsa, in caulibus prostratis abundantia, in ascendentibus nulla, rhizoids scattered, on prostrate stems abundant, on ascending ones none.

Macronema,-atis (s.n.III), abl. sg. macronemate, nom. & acc. pl. macronemata: (in bryophytes) macronemata, the large, freely branched rhizoids on stems or leaf bases located in the leaf axils and branch insertions, especially in the genus Rhizomnium.

Micronema,-atis (s.n.III), abl. sg. micronemate, nom. & acc. pl. micronemata: (in bryophytes) “small, thin, sparsely branched rhizoids produced on the stem between leaves” (Magill 1990), especially in the genus Rhizomnium.

Radicle, q.v., (in mosses) slender, nonchlorophyllose threads attaching the plant to the substrate. They often cover stems and occur in places along the leaves, including the leaf tips; in liverworts and hornworts, radicles are unicellular; also called rhizoid: radicula,-ae (s.f.I.), abl.sg. radicula, nom. pl. radiculae.

Radix,-icis (s.f.III), abl.sg. radice: the root; formerly used for the ‘roots,’ i.e. the rhizoids, of mosses:

- [Phascum stellatum] subacaule macrorhizon; Radices longiusculae, simplices. (C. Muell.), [Phascum] nearly stemless, with large rhizoids. The roots rather long, simple [i.e. unbranched].

Rhizidium,-ii (s.n.II), abl. sg. rhizidio: “term suggested for rhizoid in the oophore condition (Bower)” (Jackson).

Rhizina,-ae (s.f.I), abl.sg. rhizina, nom. pl. rhizinae: rhizine, “(obsol.) the young roots of Mosses and lichens” (Lindley); (fungi) “a term at one time used for a ‘rhizoid’ or an attaching rootlet; also, a roolike hair or strand” (S&D).