One

one

 

[wuhn]

adjective

being or amounting to a single unit or individual or entirething, item, or object rather than two or more

sin·gle

 [sing-guhl]

adjective

only one in number; one only; unique; sole

The two words essentially mean the same thing, but have somewhat different connotations.

[Photo by Aethiopica]

When I picture "one" flower, I see just a flower. No particular background, no significant detail beyond the flower - one flower, beautiful in its simplicity. 

[art.com]

When I picture a "single" flower, I see one flower, but a flower in a field with no end in sight, all grass, rocks, and sky - and the one, solitary, single flower. 

One is just one, but single is alone. It's a rather depressing word to use to describe oneself when you think about it.

But then, it's better than being lone.

lone

 

[lohn]

adjective

         being alone; without company or accompaniment; solitary; 

         unaccompanied; standing by itself or apart; isolated

When there is a "single" or "lone" flower, it is alone - but it is rarely seen this way. Instead, that lone flower growing in the desolate valley is a symbol of strength, the single rose elegant in its simplicity.

[cafleurebon.com]

Perhaps the lone flower isn't so terrible after all.

[definitions from dictionary.com]