Alocasia macrorrhizos "Black Stem"
In early July 2007, we encountered a large specimen of this plant and discovered with delight that it was entering a blooming cycle. Therefore, the opportunity to hybridize with it has arrived and so I have added this plant to our list. Up until now, I have never seen this plant in bloom, although I have spoken with at least one individual who claims to have seen it in bloom. My firsthand observations of these inflorescences has shown me that the spathe is green with the exception of the swollen area surrounding the pistillate flowers, which is purplish in color. The spadix is white in color. The first hybridizations with this plant involve pollen from both A. "Borneo Giant" and A. alba applied to pistils of the A. "Black Stem".
This plant is one of the many varieties of A. macrorrhizos and is fairly widely available. Our experience with this plant is that it does poorly in the wintertime and, therefore, is not hardy enough for use in areas other than warm tropical ones. Our objective is to get the petiole and main vein coloration onto a hardier plant and thus make this new plant available to summertime tropical plant fanciers who do not live in a tropical climate.
Above is a front view of the freshly opened inflorescence.
A side view of an earlier inflorescence. Note the purplish basal area in both photos. We have since been able to collect pollen from this inflorescence. This pollen has been used in work with Alocasia macrorrhizos 'Borneo Giant' and Alocasia alba. Reciprocal crosses of these two species onto the Alocasia macrorrhizos 'Black Stem' have also been performed.
Above are pictured the nearly ripened berries from the hybridization described here.