I've managed to get a bit of spare time so I'll make a start on Australian orchids. There are (according to the authorities) about 1400 species of orchid in 192 genera in Australia. In the more southern areas there's a preponderance of terrestrials, with epiphytes (and/or lithophytes) dominating the more northern and tropical regions. In the region where I am there's only about 40 native orchids, which is still pretty good compared to places like Hawaii where there's only 3 native species of orchid.
My local climate is equatorial monsoonal, with two distinct seasons, the wet and the dry. The wet season is wet, humid and hot. The dry season is dry and hot, but nights are cooler. That's why the majority of the orchids here are terrestrials and deciduous. Some live in seasonal swamps where they often go under water. Come the dry season and you won't see anything. Even the epiphytes can lose some of their leaves in the dry. Although, the epiphytes usually flower in the dry season whereas the terrestrials flower in the early wet season and between floods.
This is a current list of our local species (I won't add a list of all the Australian species).
Arthrochilus latipes
Calochilus caeruleus
Calochilus holtzei
Chiloschista phyllorhiza
Cymbidium canaliculatum
Dendrobium affine
Dendrobium canaliculatum
Dendrobium lobbii
Dendrobium trilamellatum
Dipodium stenocheilum
Didymoplexis pallens
Eulophia bicallosa
Eulophia graminea
Geodorum neocaledonicum
Habenaria elongata
Habenaria ferdinandi
Habenaria halata
Habenaria hymenophylla
Habenaria mesophylla
Habenaria ochroleuca
Habenaria rumphii
Habenaria sp. Sand flats (undescribed)
Habenaria triplonema
Malaxis acuminata
Malaxis latifolia
Malaxis marsupichila
Nervilia aragoana
Nervilia holochila
Nervilia peltata
Nervilia plicata
Nervilia sp. Cordata (undescribed)
Nervilia uniflora
Pachystoma pubescens
Phaius terrestre
Phoringopsis byrnesii
Phoringopsis sp. Bradshaw Station (undescribed)
Spathoglottis paulinae
Thrixspermum congestum
Tropidia curculigoides
Zeuxine oblonga
