A Grammatical Dictionary of Botanical Latin

Rimoportula,-ae (s.f.I), abl.sg. rimoportula (diatoms): labiate process [> L. rima,-ae (s.f.I): fissure, crack, cleft + portula,-ae (s.f.I), a small gate, passage, entrance or outlet; the ‘fissure’ perhaps refers to the slit between the lips of the opening]; see ‘pore’].

Processus (s.m.IV) labiatus (adj.A), abl. sg. processu labiato [> L. labiatus (adj.A), ‘lipped’ in allusion to the lip-shaped opening of the rimoportula on the internal valve face of some diatoms].

“A tubular process through the valve of some diatoms. On the internal valve face, the rimoportula opening has the shape of a pair of lips. On the external valve face, the rimoportula opening may be a simple, round aperture at the valve surface or it may be a tube extending out from the valve. Plural form is rimoportulae. Rimoportulae are found in centric genera such as Stephanodiscus and Aulacoseira; in araphid genera such as Diatoma, Hannaea, Meridion and Tabellaria; and in eunotioid genera such as Actinella, Amphorotia, Eunophora, and Eunotia. Rimoportulae extrude polysaccharides and other carbon compounds. They are considered to have appeared relatively early in diatom evolution, but to have been lost in a number of more advanced, raphid groups.” Spaulding, S.A., Lubinski, D.J. and Potapova, M. (2010). Diatoms of the United States. http://westerndiatoms.colorado.edu Accessed on 21 March, 2017].

Jelly pore: used in Diatom morphology for ‘rimoportula’ by Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13. [sec. Spaulding, S.A., Lubinski, D.J. and Potapova, M. (2010). Diatoms of the United States. http://westerndiatoms.colorado.edu Accessed on 21 March, 2017].