Taxonomy
Between 1881 and 1905, Frederick Manson Bailey described 11 species of Nepenthes from northern Australia, all of which were placed in synonymy with N. mirabilis by B. H. Danser in 1928. The only taxon which Danser considered to possess morphological characters atypical of N. mirabilis was N. rowanae. He wrote:
Of all these I have seen the type or at least authentic specimens, but they are nearly all mere growth forms of N. mirabilis. Only N. rowanae shows a character not yet met with in N. mirabilis, viz. campanulate-infundibuliform upper pitchers. A similar aberration, however, is often met with in several allied species and is certainly insufficient for specific distinction.
However, field observations carried out between 2001 and 2003 "showed that N. rowanae possesses several stable, significant morphological and ecological characteristics that are not exhibited by N. mirabilis", and the taxon was subsequently elevated to a species in 2005. This opinion is not universally shared; taxonomist Jan Schlauer continues to treat N. rowanae as a heterotypic synonym of N. mirabilis in his Carnivorous Plant Database.
| Character | N. mirabilis | N. rowanae |
|---|---|---|
| Morphology of leaf blade | Acute to rounded | Contracted towards the apex, then continuing along the tendril as a narrow, acute, extension |
| Insertion of tendril to leaf blade | Simple | Peltate |
| Pitcher wings | Simple, bearing multicellular fringe elements | Often flattened at front, forming a T-shape in XS, multicellular fringe elements often present |
| Leaf blade texture | Usually chartaceous | Strongly coriaceous |
| Leaf blade attachment to stem | Simple, or rarely decurrent for ⅓ the length of the internode | Decurrent for at least ½ the length of the internode, usually more |
| Gland density in lower portion of pitcher | 1600-2500 / cm² | Approximately 3600 / cm² |
| Position of pitcher hip in upper pitchers | Mid-way, to lower half | Upper quarter |
| Position of pitcher hip in lower pitchers | Lower third to quarter | Immediately beneath peristome |
Read more about this topic: Nepenthes Rowanae