The International Nepenthes Grex Registry

PICTORIAL DESCRIPTIONS AND THE INSUFFICIENCY OF THE TAXONOMIC METHOD

The most powerful aspect of the INGR is its reliance on pictorial descriptions. A plant is primarily defined by its pictures and then secondarily defined by it taxonomic description. The advantages of this methodology are best illustrated by a few examples:

Example 1: N. x Splendiana

N. x Spendiana is a hybrid created by Bruce Bednar. The derivation of N. x Splendiana is, according to records, N. kampotiana x maxima. This may seem straight forward enough at first glance, but upon closer examination, this apparent clarity begins to become clouded. Up until very recently, the certainty of taxonomic definition with regard to the species of the SE Asian countries has been anything but certain.

There are a great number of Nepenthes hybrids that have been defined as progeny of N. thorelii, N. kampotiana, N. smilesii, etc. These plants were bred and the parental species identified in good faith according to the taxonomic references of the time. This would be all well and good if Nepenthes taxonomy was a static, consistent and complete practice, but it is not. Rather, Nepenthes taxonomy is evolving, at times inconsistent, far from complete, and although the situation is improving, it does not provide the degree of characteristic specificity necessary to a modern breeding record.

Mr. Bednar identified the female parent of N. x Splendiana as N. kampotiana, and he was correct in doing so. The female plant he used did not change in the subsequent years; only the taxonomy did. Now, in retrospect and in light of new taxonomic formulations of SE Asian plants, we are tempted to ask “Was the 'N. kampotiana' used by Bednar in N. x Splendiana really the N. kampotiana as it is defined today? Or, was what was called N. kampotiana at the time really N. smilesii, or N. bokorensis, or some other species?” Because there are no pictures or even drawings of the particular female plant used to create N. x Splendiana, we will probably never know the answer to the above questions with any certainty.

This example has been used in the past to clarify the power of a breeding registry based on pictorial definitions. In this case, emphasis has always been placed on the uncertainty of the female parent N. kampotiana. However, in recent years, the Nepenthes community has witnessed the unfolding of a different kind of uncertainty with regard to the male parent of N. x Splendiana. In the case of the female N. kampotiana, our uncertainty is in regard to species classification: was the plant really N. kampotiana as we define it today, or another related species wrongly classified? In the case of the male N. maxima, the uncertainty of characteristics arises not from a question of species assignment but rather from a question of species specificity. In recent years, many previously unknown populations of N. maxima have been identified, and the range of secondary characteristics exhibited in those newly examined populations (color, pitcher shape, plant size, growth characteristics) has changed what was once considered a clearly defined species into one of the more dynamic Nepenthes taxa with a much wider spectrum of characteristic expression than previously recognized.

In brief, the preceding example makes these two points clear:

  1. That taxonomic definitions are too dynamic and lacking the degree of characteristic specificity necessary to a modern breeder’s system of record.
  2. That the pictorial definitions of the INGR system of record is superior to systems based upon taxonomic definition in providing singular definitions of each hybrid derivative in a grex. Species are, by definition, group designations over an often, at least from the breeder’s perspective, wide range of possible characteristic expressions. The pictorial definitions provided by the INGR methodology is definitive and singular, which is exactly what is needed in a breeder’s system of record.

Example 2: N. alata x truncata

Just how many N. alata x truncata greges are out in the world today? Sam Estes has made this cross multiple times with different (from the breeder’s perspective) N. alata. Geoff and Andrea Mansell have made this cross with “different” N. alata, and this hybrid combination was made numerous times in Japan and elsewhere. Furthermore, there exist natural hybrid combinations of N. alata and N. truncata in the wild.

As in the previous example, a very few years have made for a very different situation. Once again, what would appear to be clearly defined by taxonomic methodology is, in a breeder’s application, nebulous and lacking in definitional specificity. The once apparently singular species N. truncata has in recent years been broadened to accommoidate a much wider range of characteristic expressions both physically and environmentally to include newly discovered populations. We now have “red”, “black”, highland and lowland, terrestrial and epiphytic N. truncata (plus the new N. truncata-like species, N. robcantleyi).

The species N. alata (N. extincta, kitanglad, kurata, leyte, micramphora, etc.) has and continues to morph into a small family of species with (again from a breeder’s perspective), a very wide range of definitional characteristics and expression potentials. The lack of definitional specificity in the species N. alata makes for a range of characteristic expression far too wide of be of much use to the breeder. To use examples from registered greges, N. Kona and N. St. Conrad are two greges with the same taxonomic derivations but with distinctly different characteristic expressions. To consider them the same, both as just N. alata x truncata, would be to ignore their obvious and distinct differences in expression and be of little use to the breeder trying to refine or accentuate desirable characteristic expression in future generations. In order to facilitate purposeful breeding, a system of record must document the characteristics of a singular plant, and the widening definition of N. truncata along with the taxonomic splintering of the species N. alata only further exacerbates the difficulties in this effort.

N. alata, N. rafflesiana, N. maxima, N. ventricosa and N. mirabilis are obvious in their descriptive deficiency, but it is a matter of degree. To a greater or lesser extent, this insufficiency is true of all species. Less obvious insufficiencies are also found in species that, at first, might seem to be unambiguous. Even well and newly defined species like N. bokorensis can display a very wide range of characteristic expression, and it is exactly these individual differences of expression that are at the heart of Nepenthes breeding and record keeping.