Palms   Chamaedorea tenella II

The Inclusion of Chamaedorea tenella with Chamaedorea geonomiformis

Taxonomists have recently made changes within the Chamaedorea Genus, one in particular is the inclusion of C. tenella with C. geonomiformis . (see Kew Checklist) For the purpose of this article I'll still refer to separate species to help with understanding however I do feel that for cultivation purposes C. tenella should be referred to as the miniature form of C. geonomiformis . I have been growing both C. tenella and C. geonomiformis for quite some time and initially had trouble seeing how they can be one and the same species. Admittedly, florally they are both very similar but flower at separate times from each other and in different manners. The male inflorescence of C. geonomiformis matures differently by the flowers gradually reaching anthesis (the point of releasing or receiving pollen) from the ends of the rachiallae back up to the beginning or fixed point of the peduncle, in sequence. The male flowers of C. tenella reach anthesis in unison. The female flowers in both species reach anthesis in unison.

Figure 1. C. tenella (3&4) and C. geonomiformis (1&2)

A few "text books" state that the male inflorescence of C.tenella has a singular or spicate inflorescences where as the inflorescences of C. geonomiformis are always branched (apart from young plants) however, this is not the case. As mature male plants of C.tenella increase in height and age, the inflorescence becomes branched adding to the cause of classing C. tenella and C. geonomiformis as one and the same.

The vegetate characteristics of both species are very different from each other. The most obvious is physical size in every reference.

Leaf size and shape differ greatly,
C. geonomiformis - long and narrow (around 100 x 300mm), lightly toothed (if at all), thick with a dull sheen. leaves on average number from 5-8 at any one time. C. tenella - short and rounded ( around +/-75 X 100mm), strongly toothed, thin and glossy. leaves on average number from 7-14 at any one time.

Petioles;
C. geonomiformis +/- 125mm C. tenella +/- 25mm, to the point of almost being non existent

Stem;
C. geonomiformis +/- 12mm in diameter C. tenella +/- 6mm in diameter.

Seed shape, size and colour changes are exactly the same between both species.

I've numbered the plants 1 through 4 to help show variation (see attached photos)

Plant 1 C. geonomiformis , male, 2002 seed, 8 inch pot for scale
Plant 2 C. geonomiformis , female, 2003 seed, 5 inch pot
Plant 3 C. tenella , female, 2002 seed, 5 inch pot
Plant 4 C. tenella , male 2003 seed, 5 inch pot

Obviously , my "growth" comparisons are based on cultivated plants which do vary in size and leaf shape.

Figure 2. C. tenella (3) and C. geonomiformis (1).

When discussing this with Don Hodel, Don stated "If you could have the luxury of surveying all the specimens of C. tenella and C. geonomiformis in the wild and herbaria you would realize that there is much variability that blurs the boundaries of the two. As keen growers of these plants, we have a tendency to pick out or zero in on differences that seem major and "pigeon hole" our various plants into known and recognized categories (species). However, if we could see the entire range of variability in these species, seemingly major differences become minor. From a Horticultural point of view they are very distinct but from a Taxonomists point of view they are one and the same variable species".

Figure 3. C. tenella (3&4) and C. geonomiformis (1&2)	Figure 4. C. tenella (3) and C. geonomiformis (1)
Figure 5. C. geonomiformis (1)	Figure 6. C. tenella (4)

Contributed by:

Jason Cox, Kami Palms (Text and Figure 1,2,3,4,5&6)

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