The text says "speakers" because that's how Realtek High Definition Audio registers itself. Realtek is apparently responsible for the headphones port, so the device plugged in there gets called whatever they say. (It is my understanding that devices plugged into those ports do not identify themselves by brand/model/form-factor.)
Related: "why doesn't it show a different icon if I have dual headphones (output with mic)?"
The volume control displays a speaker icon, not a combined speaker/microphone icon, because that slider only controls output volume. To see this, open Sound and highlight your default device.
Click Properties, then switch to the Levels tab. Notice how the top slider has the same value as the taskbar volume control.
Back in Sound, switch to the Recording tab. Do the same thing, opening your selected device's properties and looking at the Levels tab.
Notice how this value is independent from your output volume.