| Morphological characters including the glandular indumentum and cream flower colour suggest that A. ambiguum is close to A. graniticum. |
| In most species the leaves are covered in fine hairs or indumentum, which normally contain the essential oils. |
| The indumentum of petioles consists of scales and trichomes. |
| An excellent compact plant with pale green leaves felted with brown indumentum on the reverse. |
| An indumentum was noted in the inflorescence region or in the upper part of the stem. |
| It is variable in size and indumentum of culms, leaves, and panicles. |
