Excerpts from Jim Conrad's
from the September 4, 2005 Newsletter issued from the Sierra Nevada foothills
somewhat east of Placerville, California, USA
Another striking bush met in a shadowy forest at about 4500 feet caught my attention not because of its flowers but because of its fruits. Two shiny-black, globose, juicy, pea-size but bad-tasting berries always appeared together side by side at the tip of a slender branch, each fruit pair subtended by a single dark purple, flaring, collar-like bract. The purple bracts caught one's attention, then the black fruits' presence surprised you, being so black in the dark forest that they were invisible but for the shine on them. You can see all this at http://www.paghat.com/berries16.html.
It took me a while to realize that this exotic-looking plant was a bush honeysuckle -- LONICERA INVOLUCRATA, graced with the appropriate English name of Black Twinberry. It's a native, mostly northern species, distributed from Quebec to Alaska, south in the mountains to Mexico.
I think most of us underappreciate honeysuckle diversity. About 180 species of the genus Lonicera are known, many are ornamental, and many are very different from the heavenly smelling but ubiquitous and invasive weed Japanese Honeysuckle, Lonicera japonica.
In the East we have the red-blossomed Red Honeysuckle or Trumpet Honeysuckle, Lonicera sempervirens, which you can see here.
On that vine a few red blossoms cluster toward the stem tip, with the stem's last two leaves before reaching the flowers usually but not always growing together at their bases, making it look like the stem passes through the center of a single rounded leaf. The Black Twinberry's collar-like bract is an evolutionary step beyond those two leaves growing together.
In fact, at the California Honeysuckles page at http://www.laspilitas.com/groups/lonicera/California_honeysuckle.htm you can see a good variety of California Honeysuckles, and it's interesting to observe how in some species the bases of the last two stem leaves before the flowers are completely grown together, only partly so on some species, and not at all on others. There seems to have been a definite evolutionary impulse among the honeysuckles to have those last two leaves joined, with the Black Twinberry representing an ultimate perfection.
If you could have seen how pretty the Black Twinberry's fruiting clusters were there in the cool, dark, high- elevation coniferous forest, you might have come up with that notion yourself.