Bulbophyllum umbellatum

Bulbophyllum umbellatum appears to be somewhat uncommon in cultivation.  When you google it, you don't see many correctly identified photos of this species.  There is also some confusion about the name.  There used to be a species called Cirrhopetalum umbellatum.  Cirrhopetalum is now included in genus Bulbophyllum, and the current name for Cirrhopetalum umbellatum is Bulbophyllum longiflorum (link to the photo in IOSPE).  But some people are incorrectly calling them Bulbophyllum umbellatum.

According to Flora of China, this species occurs in southern part of China, Bhutan, NE India, Myanmar, Nepal, Thailand, Vietnam, and Taiwan at the elevation range of 1000-2200 m.

I got my plant from Troy Meyers as a seedling about 5 years ago ('MC411' x self).  The seeds were from Dale Border, so my plant is likely to be the offspring of plant in IOSPE, whose photo was taken by him.  I think this is the second blooming under my cultivation.  It is a fairly slow grower for me, and it doesn't retain leaves well. I'm growing it in at the cool-end of intermediate temperature; the max/min daily temperature is 29/18C (84/65F) in the summer and 21/13C (70/55F) in the winter, and I wonder if it needs more warmth.

There are several similar species.  Indeed, several orchid vendors have been selling incorrectly labelled B. guttulatum as B. umbellatum.  I saw a nice table comparing this species with other related species (Ya et al 2019) when I was trying to confirm the identification of my plant.  According to this table, B. umbellatum is supposed to have emarginate (notched) leaf tip (apex) and B. guttulatum has round leaf apex.  However, my plant has round leaf apex.  The color of flowers seem to match with B. umbellatum since B. guttulatum has purple spots on the petals and sepals and the lip is also purplish.  However, color could be unreliable since some individuals might be pale (e.g. albino).  Keys in Flora of China (link) uses the shape of wings under the column: acute (pointy) for B. guttulatum vs round wings for B. umbellatum. My plant has the round wings like B. umbellatum.

After looking at illustrations at Swiss Orchid Foundation, my plant is likely to be correct B. umbellatum. Also, B. guttulatum has a long, thread-like, pointy part at the tip of the column (just below the anther cap; see the linked illustration below), which my plant doesn't have.  This column structure seems to be the easiest way to distinguish these two species (other than color differences of the flowers).  Additionally, their illustration doesn't seem to show pronounced notched leaf tips, suggested by Ya et al (2019) for B. umbellatum. So I'm pretty sure my plant is not a pale form of B. guttulatum, and it is B. umbellatum.  There is also another similar species described recently from Myanmar, B. putaoensis (link to PDF, which contains photographic comparison showing difference in the petal shape).

B. guttulatum with the pointy column tip (see panels b and c).

© G. Seidenfaden. 1992. Bulbophyllum guttulatum (Hook.f.) N.P.Balakr.. Swiss Orchid Foundation at the Herbarium Jany Renz. Botanical Institute, University of Basel, Switzerland.

B. umbellatum (type) has much less pronounced pointy part under the anther cap (see panel e).

© G. Seidenfaden. 1973. Bulbophyllum umbellatum Lindl.. Swiss Orchid Foundation at the Herbarium Jany Renz. Botanical Institute, University of Basel, Switzerland.

© G. Seidenfaden. 1973. Bulbophyllum umbellatum Lindl.. Swiss Orchid Foundation at the Herbarium Jany Renz. Botanical Institute, University of Basel, Switzerland.

 

Literature cited:

• Ya, J. D., Guo, Y. J., Liu, C., Cai, J., Dong, G. J., Jiang, H., & Li, D. Z. (2019). Bulbophyllum reflexipetalum (Orchidaceae, Epidendroideae, Malaxideae), a new species from Xizang, China. PhytoKeys, 130, 33. (link to full text)