Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Tribe: Podochileae
Subtribe: Bulbophyllinae
Genus: Bulbophyllum
Species: B. pygmaeum
Binomial name: Bulbophyllum pygmaeum
Synonym: Ichthyostomum pygmaeum
Common names: Pygmy tree orchid, Bulbophyllum

Bulbophyllum pygmaeum is a small, native, orchid that is epiphytic (on tree trunks), or rupestral (on rocks and cliffs) forming widely spreading mats. The leaves are about 5mm long and 3mm wide.
It is endemic throughout New Zealand including the Three Kings, and the Stewart Islands.
It has green pseudobulbs (3-5 mm diameter), each bearing a single leaf arising from the top. These pseudobulbs are linked by rhizomes to form a mat.
During early summer it produces small, white flowers (>2mm across). The flowers are self-pollinating.

Growing in the Te Henui Valley.
[1] 

The green pseudobulbs.
  

Thanks to Wikipedia for text and information:https://creativecommons.org/licenses/by-sa/3.0/