By a consistent registering of vernacular names for algae, we have documented 156 marine phytonyms along eastern Adriatic for macroalgae and Zosteraceae, including a half of local synonyms between different islands and mainland areas, and 82 names for different marine taxa. Therefore Croatian vernacular names of marine algae are the most numerous within Europe, their richness being subequal to the maximal one for Japanese algae. A minor amount of these marine phytonyms are Romanic loans (1/5 to 1/3), half of them are of Slavonic origin, and the rest are pre-Romance-non-Slavic archaisms of early Liburnian and Proto-Indo-European origin. The poorest stock of algal names occurs in the Dalmatian mainland with 9 Shtokavian phytonyms, and the more abundant Chakavian ones we have registered in the islands: the richest ones in southeastern Krk with 79 marine phytonyms, 25 in Rab, 19 in Dugi Otok, 15 in Vis, 12 in @irje island, and the poorest are Mljet and Lastovo islands and the Velebit coast with 3–5 marine phytonyms.Sustavnim popisom je kod nas na istočnom Jadranu nadjeno 156 morskih fitonima za makroalge i Zosteraceae, od čega su polovica sinonimi između raznih otoka i kopna, a ostalih 82 fitonima se odnose na posebne morske svojte. Zato su kod nas imena morskih alga bogatija negoli igdje u Europi i podjednako brojna kao u najbogatijem svjetskom nazivlju za alge u Japanu. Tek manji dio toga hrvatskog nazivlja za alge su posudjeni romanizmi (1/5–1/3), polovica su čakavski nazivi, a ostalo predromansko-neslavenski arhaizmi liburno-ilirskoga i praindoeuropskog podrijetla. Kod nas je najsiromašnije štokavsko nazivlje alga na kopnenim obalama, najviše do 9 fitonima. Bogatije je čakavsko nazivlje alga na otocima: najviše je 79 morskih fitonima na jugoistočnom Krku, pa 25 na Rabu, 19 na Dugom otoku, 15 na Visu, 12 na Žirju, a najmanje (3–5) velebitska obala, Mljet i Lastovo
