Q: About rheophytic Utricularia
U. ochroleuca;
Oregon riparian
U. macrorhiza;
Nevada riparian
A: Rheophytic species are those that grow in streams, on streambanks, or on other
kinds of watercourses. I have never seen the truly rheophytic species, but I have observed
the occasional case where suspended aquatics (U. macrorhiza)
or affixed aquatics (U. gibba,
U. intermedia, U. ochroleuca) were
growing as rheophytes, but these were cases of plants growing in atypical situations. I think that true rheophytes
live in rapidly flowing, riparian areas.
About eight species of Utricularia are probably best considered to
be rheophytes: U. choristotheca, U. determannii,
U. heterochroma, U. mirabilis,
U. neottioides, U. oliveriana,
U. rigida, and U. tetraloba. Interestingly, it has been observed that rheophytes
often bear few or no bladders.
None of these species are in cultivation.
If you wanted to try to grow them, you could try a simple
Sphagnum slurry, but you are likely to be disappointed. If the plants need high levels of
oxygen, adding an aquarium bubbler might help. I bet, though, that your best changes would be had if you created a
cascading flow table, such as has been used to grow cliff-dwelling Pinguicula hirtiflora.
Page citations: Barthlott, W. et al. 2007;
Peruzzi, L. et al. 2004; Rice, B.A. 2006a; Taylor, P. 1989.
