| Subject | English | Danish |
| med. | Alder anomalia of granulation | Alder-Reilly's syndrom |
| nat.sc., agric. | alder buckthorn | tørst (Rhamnus frangula) |
| bot. | alder buckthorn | tørst (Frangula alnus Mill.; Rhamnus frangula L.) |
| nat.sc., agric. | alder bud moth | birkesækmøl (Coleophora fuscedinella) |
| life.sc., agric. | alder froghopper | elleskumcikade (Aphrophora alni (Fall.)) |
| nat.res., agric. | alder leaf-beetle | ellebladbille (Agelastica alni) |
| life.sc., agric. | alder leaf-gall mite | ellebladgalmide (Eriophyes laevis (Nal.)) |
| life.sc., agric. | alder moth | elleugle (Acronicta alni (L.)) |
| life.sc., agric. | alder psyllid | ellebladloppe (Psylla alni (L.)) |
| forestr. | alder-tree | el (Alnus spp.) |
| life.sc., agric. | alder wood wasp | kamelhveps (Xiphydria camelus (L.)) |
| agric. | ash-alder wood | alluvial skov |
| agric. | black alder | rødel (Alnus glutinosa) |
| agric. | common alder | rødel (Alnus glutinosa) |
| agric. | European alder | rødel (Alnus glutinosa) |
| nat.sc., agric. | European green alder | grønel (Alnus viridis) |
| nat.sc., agric. | gray alder | hvidel (Alnus incana) |
| nat.sc., agric. | green alder | grønel (Alnus viridis) |
| bot. | grey alder | hvid-el (Alnus incana (L.) Moench; Alnus incana (L.) Moench var. borealis Norrl.; Alnus incana (L.) Moench var. virescens Wahlenb.; Alnus kolaënsis N. I. Orlova (ssp. kolaënsis)) |
| nat.sc., agric. | grey alder | hvidel (Alnus incana) |
| bot. | grey alder | grå-el (Alnus incana (L.) Moench; Alnus incana (L.) Moench var. borealis Norrl.; Alnus incana (L.) Moench var. virescens Wahlenb.; Alnus kolaënsis N. I. Orlova (ssp. kolaënsis)) |
| nat.sc., agric. | hazel alder | rynket el (Alnus rugosa, Alnus serrulata) |
| nat.sc., agric. | hazel alder | hasselel (Alnus rugosa, Alnus serrulata) |
| life.sc., agric. | Italian alder | hjertebladet el (Alnus cordata) |
| forestr. | Oregon alder | oregon-el (Alnus oregona, Alnus rubra) |
| forestr. | Oregon alder | amerikansk rødel (Alnus oregona, Alnus rubra) |
| forestr. | red alder | oregon-el (Alnus oregona, Alnus rubra) |
| forestr. | red alder | amerikansk rødel (Alnus oregona, Alnus rubra) |
| nat.sc., agric. | smooth alder | rynket el (Alnus rugosa, Alnus serrulata) |
| nat.sc., agric. | smooth alder | hasselel (Alnus rugosa, Alnus serrulata) |
| nat.sc., agric. | speckled alder | hvidel (Alnus incana) |
| agric. | speckled alder mildew | gråelmeldug (Erysiphe vernalis) |
| forestr. | western alder | amerikansk rødel (Alnus oregona, Alnus rubra) |
| forestr. | western alder | oregon-el (Alnus oregona, Alnus rubra) |
