X-axis with non-numeric/datetime values?

I'm trying to create a microchart with a bar series that has string,decimal pairs. 

"Apple", 10M

"Orange", 7M

"Pear", 8M

etc.

Is it possible to create this chart? I'm getting the error "Type 'System.String' is not a supported axis type.".

MicroXYChart chart = new MicroXYChart();
Dictionary<string, decimal> values = GetValues(item);
MicroBarSeries series = new MicroBarSeries();
series.ItemsSource = values.ToArray();
series.XPath = "Key";
series.YPath = "Value";
chart.IsHotTrackingEnabled = true;
MicroSeriesPaletteStyleSelector microSeriesPaletteStyleSelector = new MicroSeriesPaletteStyleSelector();
microSeriesPaletteStyleSelector.Palette = new MicroPalette(MicroPaletteKind.Default);
chart.SeriesStyleSelector = microSeriesPaletteStyleSelector;
chart.Series.Add(series);