White clover populations collected from the Caucasus region and eastern Turkey were compared with seven white clover cultivars in a moist, lowland, highly fertile environment. The Caucasus collection came from 15 sites below 1000 m and 19 sites above 1000 m; all seven sites in Turkey were above 1000 m. The populations were generally small leaved and except for those from low altitude sites in Dagestan and Azerbaijan populations were acyanogenic. None of the collected populations were significantly higher yielding than 'Grassland Huia' in any season. However, several populations from the Caucasus were higher yielding than 'Kent Wild White' and similar to that of 'Grassland Tahora.' Survival was poor with only four populations having more than 50% of plants surviving after 18 months in this environment. High altitude Caucasus populations were earlier flowering than low altitude populations, an adaptation to allow adequate seed set.
There was a negative relationship between altitude of population origin and proportion of cyanogenic plants; and between altitude and both leaf size and canopy height. High incidence of no leaf mark (vv) was associated with populations from colder rather than warmer environments. Populations from sites with low rainfall were larger leaved and more upright than populations from wetter sites. Populations from severely grazed sites were less upright and less cyanogenic than populations from infrequently or nil defoliated sites.