Not sure there is something built in, but this seems to get what you want
using Winston
x = randn(10)
function stemplot(x, args...)
n = length(x)
p = FramedPlot()
add(p, Points(1:n, x, kind="filled circle"))
map(i-> add(p, Curve([i,i], [0,x[i]])), 1:n)
add(p, Curve([1,n], [0,0]))
p
end
stemplot(x)