I do not see the meaning of une ame immortelle in the last sentence; if the words had been une ame immatérielle, it would be to the purpose.
It had been Beethoven's custom to enclose a sprig of immortelle in nearly every letter he sent her, and all these sprigs she kept in her desk many, many years.
The only immortelle I saw growing in Italy, I found so near to Tasso’s oak that his foot must often have pressed the spot.
A few of the mottoes wrought into the immortelle and bead decorations will give a faint idea of the “Frenchiness” of the display.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "immortelle" in a variety of sentences. We hope that you will now be able to make sentences using this word.