Z. rosea is small. And flowers are more rounded. Difficult to grow except in really hot climates year round. Exceptional in its ability to produce hybrids. Z. macrosiphon is like a smaller Z. grandiflora/carinata/robusta but the style is erect. It is exactly the same color, an intense rose as grandiflora but in grandiflora the style is "dismayed". Z. fosteri as it has been for years in cultivation was distinct in that the color form selected, a glowing magenta pink, was selected in the wild among other color forms. Therefore if that unusual flower color is no longer around it is possible we have lost fosteri to cultivation.