There are a couple of little known trees but the most common flower is Xylobium a family of Orchids.
xeranthemum
Xtabentun is a Mexican liqueur. The ingredients include the nectar from the xtabentun flower.
there is no flower
X-rayXenonXeroxSince the question asked for "three-letter" words beginning with "X", how about "xis"?
Peony
orchid oleander
A four letter word beginning with C and ending with X is crux.
There is no synonym for awesome beginning with the letter x.
There is no country beginning with the letter "x"
Xylophone, xray,
There are no countries with the letter X as the second letter. There are also no countries beginning with the letter X.
Sage is one tye of flower.