Identification: Arrow-shaped Unknown

The species Philodendron erubescens K. Koch & Augustin has been on the books since 1854. From what I can figure out, the hybridized form has been around for approximately 30 years. The hybridized form is not the true species form. Here's a link to the information I've gathered regarding the actual species:

http://www.exoticrainforest.com/Philodendron erubescens pc.html

 

I just received an interesting message from a friend in Hawaii. As I stated above, Hawaiians often eat aroids which contain oxalate crystals. My friend was commenting on a request made on another plant board called Aroid l, but I thought it would be of interest here as well. Remember, all aroids contain oxalate crystals which are often claimed to be a deadly poison. Here's the quote, "(name removed) asked on Aroid-l about eating Colocasia gigantea petioles and I responded that it was delicious. In fact, if any aroiders wish to taste a delicious soup and they happen to be in Honolulu...they should visit a restaurant called Hale Vietnam, in Kaimuki. Order the Hot and sour shrimp(or fish) soup...awesome."

The gentleman who sent this was a personal friend of Roberto Burle Marx who created the plant mention earlier. He also maintains one of the largest collections of extremely rare aroids in Hawaii.

 

(Syngonium Podophyllum) Arrowhead Vine

 

Syngonium podophyllum is certainly the plant most commonly known as the Arrowhead Vine, but many other Syngonium species have a similar growth form, thus often are granted that common name. The plant shown here has many characteristics not common to the Syngonium group. Russ covered some and I have attempted to point out others. Due to the reddish coloration of the vine, this one is almost certainly a hybridized form of Philodendron erubescens.

 

I was doing some research on I]Philodendron erubescens [/I just this morning and ran across this entire discussion again. A lady in Hawaii recently sent me an enormous chuck of the vine from a verified P. erubescens. The cane is well over 1 inch thick! However, the plant in Hawaii is an "escapee". That plant is from Central and South America and is not native to the islands of the Pacific.

The hybrid Philodendron Red Emerald is likely 30 to 40 or so years old by now. I checked all the books in my data files and could not find an exact date. It was created by using Philodendron erubescens as the base species. I have no idea what that species was crossed with to create the hybrid. The plant receives the name "Red Emerald" due to the reddish petioles of one of the parent plants. A petiole is simply the "stem" that supports the leaf. However, Philodendron erubescens does not always have red petioles. It is variable and can also have green petioles.

I also found an interesting photo posted by a researcher in Poland who does a lot of work with the International Aroid Society. I correspond directly with this person on a fairly regular basis and have found his identifications to be quite accurate. Take a look at his information and see if this solves the mystery of what the original poster was trying to learn:

http://www.wschowa.com/abrimaal/araceum/philodendron/redem.htm

By the way, Philodendron erubescens has been used to create many hybrid variations.

 

Don't know how we just let this one die until I got an email asking for further information on this thread. Here goes: Red Emerald is a very old name for a plant commonly now accepted as Philodendron erubescens. Many hybrids were created during the 1960's with that species.

The controversy over calcium oxalate crystals will continue forever it now appears. Just too many people have copied information they have read on some internet site and posted it near verbatim without checking any scientific source. But this past week I did a major update on a species called Colocasia esculenta, the common Elephant Ear plant. During my exchanges with several botanists and aroid experts I received this quote from Leland Miyano who is a Hawaiian expert in aroids, palms and cycads. Leland has helped author several Hawaiian plant books and is a recognized plant expert in Hawaii. All forms of Colocasia esculenta contain calcium oxalate crystals just like all other aroid genera including Philodendron. If you read any child care and pet sites on the internet you'll often find this plant product (and the plant) is claimed to be a "deadly poison" as we have already discussed. It is possible for calcium oxalate crystals to burn your lips and throat but someone better explain the stuff is a "deadly poison" to the people of the Caribbean, South America, Central America, Hawaii, Polynesia and Asia since people in all those places eat it daily as a product of Colocasia esculenta! Colocasai esculenta is a staple food in those places and if you've ever been to the southeastern caribbean of Hawaii you've almost certainly eaten it. Scientific sources say cooking has nothing to do with destroying the "poison". Leland gave me a great quote which explains the situation better. In Hawaii, Colocasia esculenta is called kalo, "Kalo has two types of calcium oxalate crystals, or idioblasts,....needle-like raphides and club-like druses. It is believed that the raphides cause the mucous membrane irritations and skin dermatitis. I can speak from personal experience that eating raw kalo, leaves or corms, is not recommended. It is as if one ate fiberglass. Another warning is Agave species that have these raphides and I can attest to the extreme skin dermatitis from the sap of these...it manifests in intense itching and burning...it is a torture, that can last for many days in some people. In short, although spinach has calcium oxalate crystals, there is no comparison between them. I eat raw spinach often, but raw kalo, never. Cooked kalo is one of my favorite foods, both leaves and corms. Poi is the mashed corm and is delicious in my mind. It has been compared to library paste but some luaus cut their poi with flour and it does taste bad. The variety of kalo also determines the taste."

It is far more complicated than just eating calcium oxalate crystals, but which type of crystals are involved. Although I would not recommend anyone eat any aroid raw, even tasting cooked specimens is something that is best avoided unless ou know what you are doing. But as for being a "deadly poison", there are only a couple of cases each year of people being harmed. Of the 500 or so cases of trips to the hospital as a result, virtually no one is permanetnly harmed with the exception of the very few people who try to eat Dieffenbachia. That is quite a different story. Don't get that plant near your mouth.