South Coast Botanic Garden: Part 1 - Passiflora Misidentified

I went to the South Coast Botanic Garden today as a late birthday adventure. I had been traveling for work for two weeks back-to-back, and since it was both a beautiful day and a day that I could stay away from the office, I decided that it would be fun to traipse around there even if most of the plants weren't in bloom. Chiefly I had seen a P. caerulea picture on Yelp, so I knew there was some hunting to do. There was also a greenhouse that I discovered once there that housed several bromelias, pitcher plants, and many Passiflora especially subgenus decaloba. Many were not in bloom, but it was still fun to play "Where's Waldo". Their name plates (reproduced faithfully) were as follows:

P. Lavendar Lady
P. White Wedding
Gynura aurantiaca 'Purple Passion Vine'
P. hahnii  (=P. guatemalensis)
P. tricuspis
P. lancearia (=P. talamancensis)
P. apetala

Having seen that a couple of the species shared names, and not being as familiar with the decalobas, I returned home to investigate. It turns out that P. hahnii and P. guatemalensis are often confused, but I think I've found the answer.

"P. guatemalensis, common from Mexico to Venezuela, looks very similar to P. hahnii. For a long time they were thought to be one and the same species, and Killip (1938) erroneously mentioned P. guatemalensis as a synonym for P. hahnii. It be distinguished from P. hahnii by its stipules and shorter peduncles, and by the usual lack of extrafloral nectaries at the base of the leaf blade. While in P. guatemalensis the toothed stipules end in filiform appendages, in P. hahnii these are reduced to tiny teeth at most, or a single central tooth. John Vanderplank (1996a) points out that the flowers of P. hahnii appear singly, while in P. guatemalensis they mainly appear in pairs. This is generally true by not as dependable as the structure of the stipule." - MacDougal and Ulmer 2004

Based on the above description of the stipules and this photo, I believe the specimen in the South Coast Botanic Garden to be P. guatemalensis; not P. hahnii.

On to the next odd pair. I've found that P. lancearia is nothing like P. talamancensis, which is a difficult species for which to find information. It does however have almost identical leaves to P. helleri. So, now I have a three-way puzzle to solve. For which, I do not have an answer. Any advice is appreciated.

Another species to check would be P. tricuspis, which is commonly the misidentified P. trifasciata. Again, MacDougal land Ulmer write:

"Occasionally, one comes across a plant cultivated under the name Passiflora tricuspis that is actually P. trifasciata. These sister species can be distinguished by their leaves, though some specimens are more difficult to classify than others. In P. tricuspis, the 2 outer lobes are usually noticeably longer than the middle one."

Unfortunately, I don't have a picture in which to compare the lobes. I did get the contact information for the individual in charge of the greenhouse, so I'll be giving her a call to discuss some of these discrepancies. 

Obviously, Gynura aurantiaca 'Purple Passion Vine' is not a passion vine at all. I don't even know what to make of this, but I hope to get clarification soon.

By the way, I did find P. caerulea when I saw a immature split open fruit on the ground. Upon inspection I found the source to be a rather large vine that had been recently cut back with its surroundings. I'll have to go back sometime later to see it in bloom.