Friday, April 17, 2020

Dendrobium Mentor (polyanthum x anosmum) a primary hibrid first made in 1893

Dendrobium Mentor is a very old cross which was registered in 1893 by Veitch.  Originally it was described as a cross between Dendrobium anosmum and Dendrobium primulinum.   The plant I have is from a recent crossing.  Both species are highly variable with many varieties.   What used to be known as Dendrobium primulinum was lumped in the species concept of Dendrobium polyanthum, together with Dendrobium cretaceum (which was sometimes called Dendrobium primulinum var. alba) and other variations.   When one looks at Dendrobium primulinum var. De Leon and Den. Primulinum var. Laos, they hardly look alike, but the key feature is their huge round lips.  Technically speaking the peduncle of the flower is clavate shaped in primulinum, but this feature is too obscure for most people.   Dendrobium anosmum has too many forms and varieties to mention but perhaps only two or three have been scientifically described, var. dearei is one and var. huttoni is another.  

Given all that variability I was very curious how the flowers would look.  The plant grew in a way that is more similar to the primulinum parent than to the anosmum parent.   It produced two canes.  One of the canes produced flowers with a lip that is reminiscent, although much reduced, of the lip of primulinum, the other cane produced flowers with a shape that favored anosmum.  The flowers that resembled primulinum had a sweet fragrance with a distinct “smokey” note, the flowers that resembled anosmum barely had any fragrance.  The plant is still young, it is not clear which size it will attain when it is a full adult in two to three years.