I wrote to Bruce last week for an explanation. We'll have the story in
a few days. Many of his past Nepenthes articles in CPN lists old issues
of 100+ year old 'Gardener's Chronicles' as references so he probably
read something in one of these pertaining to the old hybrid N. x dominii
that made him believe N. hirsuta was used instead of N. gracilis. I
said that since my N. x hookeriana (??) has a slightly amplexicaul leaf
base that Bruce's speculation may be true (in a past CPN, Bruce mentions
N. hirsuta being in collections back 100+ years ago and also having an
amplexicaul leaf base).
I repotted and divided my D. binata last week as they were taken outside
for another growing season. These were D. binata and D. binata dichotoma.
They were spending the winter in a shady cool windowsill. Bunched together
with D. binata were several plants - some of these had exceptionally long
petioles, very different from D. binata and were about as long as D. binata
dichotoma petioles. Now that they've grown a bit more, I see one of these
plants is producing a multi-forked leaf (with three tips). The stalked
glands are very red like D. binata and not mostly green like D. binata
dichotoma. I assume these are hybrids D. (binata x binata dichotoma).
I kept the flowers on these last year and both these plants seemed sterile
without producing seeds, but they apparantly must have cross-pollinated
somehow.
Also, my plant of U. arenaria is flowering for the first time.