Tropaeolum notes

Jane McGary
Wed, 08 May 2013 11:16:39 PDT
The flowering season of the small Tropaeolum species I grow is coming 
to an end. I had never obtained seed from Tropaeolum tricolor before, 
but this year one of the plants found its way to the outside of the 
bulb house and climbed up the wire mesh that forms the side panel, 
where hummingbirds had access to it. Many seed capsules are forming 
on the outside flowers, and none on those inside the house. 
Apparently only birds can pollinate this species. In contrast, 
Tropaeolum brachyceras has yellow flowers that are flatter in form, 
and I saw bumblebees on these, both inside and outside the bulb 
house. It has frequently formed seeds, and most of the plants I have 
now are volunteer seedlings from my original one grown from Watson's 
collection. Bumblebees must also have come to Tropaeolum hookerianum 
subsp. austropurpureum, because it's ripening seed for the first 
time, having been grown from a Watson collection in the late 1990s. 
It will be interesting to see if the offspring show signs of 
hybridization with the similar T. brachyceras; I hope not, because 
the purple-flowered species is pretty and uncommon in cultivation.

I hope someday to obtain some of the larger, montane Tropaeolum 
species. Tropaeolum incisum came up from a discarded seed in the bulb 
frame at my former home, but I couldn't find the tuber though I dug 
around for it quite a bit. It may have plunged very deep. I bade 
goodbye to the little emerging plant the other day, having finally 
sold the house. The tropaeolum has survived three years without 
overhead protection.

Jane McGary
Portland, Oregon, USA

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