Sunday, November 23, 2008
Euonymus occidentalis
At the first pass I had no idea what this was - opposite arrangement so immediately, the options narrowed. The first individual I came across was not in fruit so based upon the leaves and buds I thought "A small Cornus nuttallii? No." Buds were dead wrong and no parallel veination. Then when I came across an individual in fruit there was no doubt: the rare Euonymus occidentalis (western wahoo/burning bush) - Celastraceae. A great place to see this species is Lewis and Clark State Park near Mary's Corner, WA - it's all along the main hiking trail that spurs off the interpretive trail. Not common enough to merit a photograph in Pojar - it's listed under Pachistima myrsinites (Oregon box) also in the Celastraceae family.
The inflorescence of the western wahoo are greenish-purplish to purplish-red (I've yet to see this in reallife - but in photographs, similar in color to the bloom of Asarum caudatum) - Hitchcock describes the flowers as "mostly 3-flowered axillary cymes". What is the fruit all about? - pictured above, with seeds covered by a reddish-orange aril (in Hitchcock - "fruit a 4-5-celled leathery capsule, seeds arillate"), Pojar describes the fruit to be similar in construction to a cashew. I was careful not to disturb the individuals I found - but if any readers have information on how this fruit is put together - I would love to hear about it. This species is of "threatened" conservation status and the ones I came across, I let be.
How about some more terms:
aril = an appendage growing at or near the hilum of a seed; fleshy thickening of the seed coat, as in Taxus.
hilum = a scar on a seed indicating its point of attachment (How great to have a term for this!)
cyme = a flat-topped or round-topped determinate inflorescence, paniculate, in which the terminal flower blooms first.
determinate = describes an inflorescence in which the terminal flower blooms first, halting further elongation of the main axis (all Harris and Harris).
Tuesday, November 18, 2008
Viburnum ellipticum
A great place to see Viburnum ellipticum (oval-leaved viburnum) is Ridgefield National Wildlife Refuge's Oaks to Wetlands Trail in the Carty Unit. At first glance I thought maybe this could be Philadelphus lewisii (mock-orange) because of the opposite arrangement and multi-stemmed, sprawling habit. But the leaves seemed too broad - leaves in Hitchcock are described as "coarsely and often rather bluntly toothed, not at all trilobed" - like the other two native species of Viburnum (Viburnum opulus, cranberry tree and Viburnum edule, highbush cranberry) - and "acutish to rounded at tip." This species is in the Caprifoliaceae (honeysuckle) family and is not very common around my parts (Thurston county), at least in my experience. If dormant, this species could also be confused with Euonymous occidentalis (western wahoo).
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