Excerpts from Jim Conrad's
from the May 31, 2015 Newsletter issued from Río Lagartos, on the north-central coast of Yucatán, MÉXICO
MEXICAN FLAME VINE
Nowadays here and there across town you find spectacularly flowering examples of the fence-climbing vine shown below at a neighbor's house:
Around here you get so used to visual explosions of red produced by bougainvillea vines that it's easy to overlook this one, which isn't a bougainvillea. Up close you see that its crimson flowering heads aren't bougainvillea-like at all, as seen at the top of this page.
They're daisy-like flowers of the Composite Family! Below, look how long, Y-shaped styles of a head's many crammed-together disc flowers form a bushy "eye" surrounded by radiating ray flower corollas:
Seen from below, the head's green, cup-like structure -- the involucre -- consists of scale-like bracts, or "phyllaries," arranged side by side, instead of overlapping like roof shingles, as it is in most composite flower involucres, shown below:
Having just one series of bracts that are not joined at their margins helps a lot with identification.
Breaking open a flower, other good field marks are found, shown below:
Note that the white, egg-shaped, cypsela-type fruits bear at their tops "pappi" consisting of many slender, white hairs. Also, no chaff-like "paleae" separate the disc flowers.
To a northern wildflower expert this combination of features brings to mind the big genus Senecio -- the groundsels. But who's ever seen a Senecio that's a woody-stemmed vine?
But, that's exactly what we have here, SENECIO CONFUSUS, often known as the Mexican Flame Vine or Orange Glow Vine, native to northern and central Mexico, but not to here in the Yucatan, though it's frequently planted here.
Senecio is a big genus, embracing over a thousand species, and they take every form, from delicate herbs to giant trees -- though the field marks mentioned above for the flowers apply to their flowers, too. If you want to expand your mind relative to groundsels, do a Google image-search on the keywords "senecio trees."
Some experts split Mexican Flame Vines from Senecio, insulting it with the despicable name Pseudogynoxus confusus.