Orchid Borealis

It's been a while since I have posted here, but I had a bit of time to take photos of my Polystachya longiscapa .  I purchased this plant from Afri Orchids in Summer 2019, and this is the second bloom under my care.  The type specimen was collected from the slopes of Lupanga Peak (Lukwangule Platerau), the southern part of the Uluguru Mountains , in Tanzania. The species are found in both northern and western slopes of the Uluguru Mountains at altitude 700-1680m as a lithophyte (Mytnik-Eismont et al. 2011).  In nature, this species is found in only this area, so it is a narrow endemic species.  Interesting, the Uluguru mountains appear to contain many plant species endemic to the area (Temu et al. 2008).    When I saw the flowers, I thought they look quite different from the typical flowers of Polystachya . Indeed, the placement of this rather taxonomically unique species has been difficult.  Some authors separated the early branching Polystachya ...

Polystachya aconitiflora occurs epiphytically or occasionally lithophytically at elevations of 1650-3000m from Uganda , Rwanda , Zaire , and the Congo (Parsons and Gerritsen, 2013, p.807-808).  It is a easy-growing, compact species with the height of about 12cm (mine is about 10cm tall).  Although the flower is relatively small (about 1cm tall), it seems to flower most of the year. The species name (species epithet) is from the similarity to the flower of monkshood (genus Aconitum ). It was described in 1942 by Summerhayes (p.295-297), and the original description can be found in Biodiversity Heritage Library ( link ).  Podzorski and Cribb (1979) treated it as a variety of another species, Polystachya vulcanica var. aconitiflora . But more recent monograph seems to treat it as a separate species (Mytnik-Ejsmont 2011, Szlachetko and Mytnik-Ejsmont 2015). P. vulcanica is much bigger (both the plant and flower size), and the leaves are beefier (semi-terete) and longer...

Polystachya pubescens is a compact and cheerful species from South Africa , Swaziland and Eastern Zimbabwe  ( link  to a distribution map).  While it is common species in South Africa, it is either rare or extinct in Zimbabwe ( Flora of Zimbabwe ).  In South Africa, it occurs in  Eastern Cape , KwaZulu-Natal , Limpopo , Mpumalanga  according to this  South African Biodiversity Institute (SANBI) site .  This is the summer rain fall region, and the plants experience a prolonged dry season during the cooler winter months (Stewart and Hennessy 1981). The genus Polystachya is a moderately large genus with approximately 250 species.  It belongs to the subtribe Polystachyinae, which is a part of the tribe Vandeae, containing  Angraecum and Aerangis in addition to Vanda , Aerides , Phalaenopsis , Thrixspermum etc.  This genus is somewhat unique since it shows pan-tropical distribution (i.e. occurs in the tropics of A...