Difficult Species Identification / Similar Species
N. murudensis - This species was thought to possibly be a form of N. tentaculata, or a hybrid of N. tentaculata and reinwardtiana. It comes from the summit area of Mt Murud in Borneo. Lower pitchers do closely resemble N. tentaculata, whereas the upper pitchers resemble a hybrid of N. tentaculata and N. reinwardtiana. Phillips and Lamb in 1988 thought that the plants where very likely hybrids between tentaculata and reinwardtiana. But by the time they published the description of N. murudensis in 1996, they had ruled out the hybrid theory, as N. reinwardtiana had not been seen around the summit area of Mt. Murud. Murudensis was formally described by Jebb & Cheek in 1997, and they separated it from N. tentaculata. In 1996, De Witte states that he found N. reinwardtiana near populations of N. murudensis (which would lend credance to the original hybrid theory.) Charles Clarke seems to accept the current species rank, even with the probable discovery of N. reinwardtiana growing nearby. Based on his Nepenthes of Borneo book, I believe that Clarke's thinking is that even if the plants are hybrids, they have become a well established entity on their own, and that in of itself may be a very good arguement for this plant to be elevated to species rank.
My own observations in cultivation seems to go against N. murudensis as being any kind of recent hybrid between N. tentaculata and N. reinwardtiana. First, N. murudensis is more difficult to grow in cultivation than either of its parents. In fact, both parents in cultivation are rather easy, whereas N. murudensis is a solid challenge. Both parents have an altitude distribution that includes lowlands as well as highlands, which is a definte reason they're easy to cultivate. Also, both parent are very common throughout their ranges in Borneo. N. murudensis, as described, only occurs around the summit of Mt. Murud, at elevations between 2200 and 2500 meters. This extremely small range in high elevations should mean the plant would require ultrahighland conditions in cultivation, and it does. It will eventually die if these conditions are not met. If the plant were a hybrid between reinwardtiana and tentaculata, then it should be easy to grow as a lowland, and should grow very well as an intermediate. Since it does not, then I conclude it is probably not a hybrid of any recent occurance. At a minimum, it may be a very very old hybrid, which has developed into its own colonies of ultrahighland plants. Even if the plant is a hybrid, its species rank should be retained. The plant has developed into well established colonies, and is not similar in cultivation requirements as its parents.
N. fallax - There has been much discussion over the status of this plant, especially recently. The confusion is between this plant and N. stenophylla. I may confuse you even more at the end of this topic, but I hope to tell you where the current status is. First, Macfarlane reduced N. fallax to a synonym of N. maxima in his monograph. Danser revised N. fallax as a synonym of N. stenophylla. This is still the "unofficial official" status, I think. Jan Schlauer has reported both on the CP Listserve and to Charles Clarke that Danser never saw an N. stenophylla specimen, and that Danser based his illustration of N. stenophylla on a specimen of N. fallax. Also, the description that Danser used for what he though was N. stenophylla was based upon a cultivated plant in which the origin is in question. In other words, the plant Danser never saw, but was described to him as N. stenophylla, could have really been N. fallax. Danser then compared this description to an N. fallax specimen, and came to the conclusion that it was the same species. In that case, an arguement could be made that N. stenophylla should be named N. fallax, and the plants now known as N. fallax could become N. stenophylla. Schlauer believes N. fallax should be retained as a species, Jebb & Cheek keeps fallax reduced to stenophylla, and Clarke follows Jebb and Cheeks interpretation for now. So far, the interpretations are based upon cultivated plants, and not field studies. Schlauer also states that practically all of the Nepenthes botanists since Danser have used Danser's monograph as the reference. This would mean that an incorrect determination by Danser has been repeatedly followed by practically everyone else to this point.
It should be noted that Charles Curtis made the original collection of N. stenophylla that was eventually used to describe N. stenophylla in cultivation. The exact location of this collection by Curtis must be seriously questioned, as he also collected N. curtisii (N. maxima) on the same trip. He stated that he collected N. curtisii in Borneo, although Charles Clarke points out that Curtis also visited Sulawesi on the same trip, and probably collected N. curtisii there. In other words, the origin of the type specimen of stenophylla is highly questionable, which is where we get to the point that the original stenophylla description may have been made on a specimen of fallax.
Confused yet? Yea, me too. Alright, so here's what I think we need to do. We need to step back and punt. It is clear that Danser's basis could have been flawed, due to the fact that the original N. stenophylla specimen that the description was based upon is being seriously questioned. I grow dozens of both plants, and there are some stable differences between the two. I note in cultivation that one plant has pitchers with orbicular lids, and the petiole area can clearly be seen down to the base. The sides of the petiole form a "V" shaped channel. (See illustrations). The other plant has more narrow lids that are not orbicular, but forms two separate identical halves which "wave" to a high point at the center of the front of the lid. These plants have a petiole area in which the sides of the petiole wrap back around to the top and the sides nearly touch or overlap (known as sheathing). My findings of the lids are backwards from what Schlauer finds (as reported in Nepenthes of Borneo), in that he states that the narrow lids are found in stenophylla. Jebb & Cheek report that the stem "sheathing" occurs in stenophylla. If this is the case, then I have my species backwards. In this case, the pitcher lid examinations I have made would match that of Schlaur.
I make no determination of if or how these plants should be separated yet, as I first want to study the reproductive structures of both plants. I would just say that there are differences in that there are differences, and they have proven consistent in dozens of cultivated plants. I also note that some species are separated by differences as little or less than these, notably N. burkeii and N. ventricosa. and field studies of where the two types of plants grow would also be a great aid in making any determination. I would also say that N. fallax should at least be "reserved" as a species, especially if locations of either it or stenophylla are in serious danger of being destroyed. We don't want to turn a blind eye. Else, we may end up classifying N. fallax as a separate species at a later date, only to find out that the last remaining colonies have been wiped out because they weren't properly protected because we had them classified as stenophylla.
Above: Closeup of the growth crown of the plant I know as N. stenophylla. This plant produces orbicular lids. Note the red square area. This part of the petiole area forms a "V" channel, and I can easily see the entire length of the petiole.
Above: Closeup of the growth crown of the plant I know as fallax. This plant produces much narrower lids than stenophylla, and note the red square area. The petiole area can not be seen as the edges roll back up and overlap or nearly touch. This area forms a sheath.
N. faizaliana - Another plant of hot discussion, this species has been closely placed to 3 other species. Adam and Wilcock placed it close to N. fusca in 1991, Jebb and Cheek placed it close to N. stenophylla in 1997, and Charles Clarke puts it close to N. boschiana. Because of the significant differences between faizaliana and stenophylla, Clarke elevated faizaliana back to species rank, but insists that further studies between faizaliana and boschiana in the field should be performed.
My own observations in cultivation mimic to a high degree that of Clarkes. First, the lower pitcher, especially the lid, is completed different from that of fusca. The uppers between the two are not similar at all. Although they can slightly resemble each other, there are enough differences between faizaliana and stenophylla (and fallax) that I can easily identify my plants in cultivation. Faizaliana can resemble boschiana closely, remembering that boschiana is quite variable in the wild as reported by Clarke. However, I can see differences in the leaves. These two species are also separated in their native locations by the width of the island of Borneo, although the type of location they grow in are very similar. I opt to keep faizaliana as a distinct species until field studies can determine if boschiana/faizaliana populations are more widespread qnd grow much closer to each other.