A Grammatical Dictionary of Botanical Latin

-stomus,-stoma,-stomum (adj.A): in Gk. comp., (in English) –stomous; having (such a) mouth; a condition of having a particular kind of mouth, pore or opening [> Gk. stoma,-atis (s.n.III), q.v., mouth];

NOTE: -stoma,-atis (s.n.III), q.v., is a Greek third declension neuter noun suffix. If used as a noun in an epithet, it would be a noun in apposition and retains its neuter gender regardless of the gender of the generic name. Since the feminine adj. ending –stoma corresponds almost exclusively with generic nouns of the feminine gender, most epithets ending in –stoma are adjectives.

NOTE: Cerasus trichostoma may seem like an exception, but the genus ‘Cerasus’ is a feminine noun in keeping with classical tradition for various trees and shrubs.

MASC. –stomus, adj. modifying a masc. noun:

Astragalus eriostomus; Campylopus microstomus; Centropogon cornutus fo leucostomus; Centropogon eurystomus; Coleus gymnostomus; Didymodon gymnostomus; Didymodon microstomus; Echites macrostomus xanthostomus; Entosthodon eurystomus; E. gymnostomus, E. plagiostomus Eriodon conostomus Fissidens gymnostomus.

NEUTER: -stomum, adj. modifying a neuter noun:

Acinodendron tetrastomum; Aconitum lasiostomum; Aconitum leucosotomum; Acromastigium anisostomum; Amomum lycostomum; Anastrophyllum leucostomum; Anomobryum leptostomum; Arisaema (n.) melanostomum; Brachymenium microstomum; Bryum eurystomum; Cephalomanes (n.) thysanostomum (Hymenophyllaceae); Crepidomanes (n.) thysanostomum (Hymenophyllaceae); Dendrobium trichostomum; Epidendrum chrysostomum; Gymnostomum erythrostomum; Macromitrium gymnostomum; Papaver (n.) macrostomum; Trichomanes (n.) thysanostomum .

NOTE: the epithets of Barbula (f.) trichostomum, Barbula trichostomum var. chlorophyllosa (Pottiaceae); Grimmia (f.) pulvinata var. gymnostomum (Grimmiaceae) and Hydropogon (m.) gymnostomum (Sematophyllaceae), may be nouns in apposition to the generic name, perhaps old generic names.

FEM. –stoma, adj. modifying a fem. noun:

Ceratolejeunea stenostoma; Cerinthe cleiostoma; Chupalon leucostoma; Cisanche jodostoma; Cobaea macrostoma; Ctenopteris leptostoma; Cuphea glossostoma, C lophostoma; C. viridostoma; Cyathodes platystoma; Dalea leucostoma; Dantonia eriostoma; Dicranella macrostoma; Dipladenia xanthostoma; Ditrichopsis gymnostoma; Effusiella trichostoma; Encalypta microstoma; Erica calostoma; Eucalyptus (f.) cyclostoma; Eugenia distoma; Eumachia trichostoma; Euphrasia phragmostoma; Ficus (f.) craterostoma; Leptorchis(f.)odontostoma; Macrocoma f.) hymenostoma; Pohlia leucostoma; Pottia eustoma; Weissia conostoma, W. gymnostoma, W. melanostoma, W. microstoma

NOTE: whether the ending of an epithet in –stoma is a noun in apposition or a feminine adjective modifying a feminine generic name may be problematic in some instances, such as when the epithet, as a noun, modified a masc. or neut. generic name, and was then transferred to a genus with a feminine gender. The –stoma ending, without further information, may then appear to be be either a noun in apposition, or an adjective.

Where noun in apposition is indicated: Centropogon (m.) chrysostoma; Cereus (m.) plagiostoma; Cinnamomum (n.) pseudomelastoma; Cleistoatus (m.) plagiostoma; Conophytum (n.) microstoma; Dendrobium (n.) sarcostoma; Desmatodon (m.) leucostoma var. muticus NOTE the variety modifies the masc. generic name, not the fem. noun in apposition); Epidendrum (n.)amblostoma; Napeanthus (m.) macrostoma; Odontoglossum (n.) x chaetostoma; Oxystegus (m.) melanostoma; Oxysophyllum (n.) macrostoma; Phoradendron (n.) ichythystoma; Prunus (f.) trichostoma; Rhytidiophyllum (n.) melastoma; Siphocampylus (m.) megastoma.

Desmatodon (m.) leucostoma var. muticus: NOTE the variety modifies the masc. generic name, not the fem. noun in apposition).

Microbryum (n.) starckeanum var. subgymnostoma; Microbryum starckeanum var. leiostoma: NOTE both varietal epithets are nouns in apposition here.