In Focus: Hoya 'Black Dragon'

Formerly called The Black Hoya

This hoya was collected from the forest of the Philippines just recently. It was first sold by the collector to foreign markets as Hoya pubicalyx 'Black Dragon'. The photo in the webside really has black corolla. A few attempts in getting it from the collector failed, but subsequent strategies let him sell me one already big plant. It was not cheap, i tell you! Of course, i almost begged him to sell me, so whatever price he quoted, i must pay. So that was the starting story of my 'Black Dragon'. 

flowers starting to burst very obviously showing the pubescent inner corolla

After two long years with constant fertilizing and extra care, it gave me two umbels. The flowers are not as black as that in the collector's website, but it is blacker than most, i suppose. So the observation continued. After many months and lots of not very black corolla color, i read in some collectors abroad that theirs purchased from the same collector also did not appear as black. Some of them were disappointed thinking they were given the wrong species, as the color sometimes are more violet than black.

 the green pedicels

At least mine showed the same characteristics of other parameters except the fully black corolla. I also realized that it was not anymore having its original name, but already changed to Hoya pubicorolla subspecies anthracina. The author said that the original Hoya pubicalyx lectotypes were not existing as they were destroyed in WW II. If that is true or not, an authority still has to make another study and changes if ever that is really reliable. 

 top is almost maroon, while bottom is darker purple almost light black

 If you do not know that the previous 2 photos came from the same plant, you will say they are different! They are both from the same plant, but flowers from different months.

I have a theory that as time goes on the media becomes more acidic, changing the hue from bluish black to reddish. These pigments, being anthocyanins, are very susceptible to change in pH. So i am trying to bring back the black color by alkalinizing the media, however i am not at home most of the time, so it is not done competently. I hope i can do it more religiously when i will be staying at home longer. My color change are changing a bit, but not really very conclusive yet.

 Even the shapes of the individual flowers look different sometimes. Look at the above photo and compare it with the photo above it. They don't look the same, do you agree? But again, they came from the same plant. I know, they are all mine, i took all the photos with the same light setting. The hue differences are obvious to the naked eye in person.

The plant showing the shiny fully green leaves , veins not evident except the midrib. It grows luxuriantly vegetative with a few umbels when fully mature. The good thing here is the continuous flowering once it started, not many simultaneous umbels but continuously. 

The details of the botanical descriptions are here: Kloppenburg, RDK. Hoya New, vol. 1-2, Dec 2013.

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