Orchid Borealis

Angraecum viguieri is native to northern and central Madagascar (Province of Antsiranana and Toamasina , Cribb & Hermans 2009).  Thy occur in Humid, evergreen forest on plateau and mossy ridge-top forest from the elevations of 900-1100m.  Based on the elevation range, I was growing it at a warm end of intermediate temperature for 7 years; the max/min daily temperature is 29-27/21-24C (80-85/70-75F) in the summer and 18-21/16-18C (65-70/60-65F) in the winter.  It kept growing, but I didn't get any flowers.  In September 2021, I removed it from the mount and potted it.  That's why the stem has the bonsai-like bent.   I also moved it to a cooler area; the max/min daily temperature is 29/18C (84/65F) in the summer and 21/13C (70/55F) in the winter.  And I finally got rewarded with the fragrant flower this year.  The cooler area also gives more seasonal variation in the temperature, compared to the relatively constant temperature of the basement....

Angraecum popowii is endemic to Madagascar .  It is from shady, highland Uapaca bojeri forests of Antananarivo , Fianarantsoa , and Toamasina (Cribb and Hermans, 2009).  The elevation range is 1200-1500m. According to the artificial key to section Aranchnangraecum by Cribb and Hermans (2009), the channelled semiterete leave is one of the key trait to distinguish this species from two related species,  A. linearifolium and A. teretifolium . The later two species have terete leaves, and the leaves are not obviously channelled, so this is a trait which can be used to differentiate without flowers.  In the photo below, I tried to show this channel on the top side of the leaves. Once they flower, A. linearifolium can be easily distinguished from the other two since it has completely different, spidery flowers.   A. popowii and A. teretifolium show similar flower shapes, but A. popowii has a larger flower; the sepal lengths are 30mm for A. popowii , 1...