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Key to Eryngium
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40677
1 Inflorescence unbranched, the heads solitary on peduncles from the leaf axils of the prostrate to erect stem. | |
3 Heads subglobose or hemispherical when fully developed, about as wide as long; bracts subtending the head barely extending beyond the base of the head; main stems leaves linear, narrowly elliptic, narrowly oblanceolate, sometime tricuspid apically | |
3 Heads cylindrical, longer than wide; bracts subtending the head longer than the radius of the head, thus extending conspicuously beyond the base of the head; main stem leaves elliptic, broader than above | |
4 Basal and cauline leaves (all, or at least many of the cauline) definitely deeply lobed into 3 or more divisions, < 10 cm long; leaf lobes tipped with moderately stiff to very stiff spine tips. | |
7 Heads 20-35 mm tall, purple to reddish; heads capped with conspicuous (1-2 cm long) spinescent bracts | |
7 Heads 4-15 mm tall, bluish to purplish; heads capped with a few, mostly entire, spinescent bracts, or lacking them. | |
10 Plants stout, fleshy, usually glaucescent; basal leaves 10-25 cm long and wide, pinnately or pinnate-ternately divided into > 7 segments, the cauline leaves similar but reduced in size and number of divisions; heads 10-15 mm in diameter; [rare ballast waif of disturbed ground]; [subgenus Eryngium] | |
11 Basal leaves pinnately lobed; stems decumbent at base, ascending (the mature plant often wider than it is tall); stems leafy throughout their length, usually with 10 or more leaves; [dry pinelands and scrub of the Coastal Plain of e. GA, s. AL, and FL] | |
15 Styles 3.0-4.0 mm long at maturity, scarcely exceeding the bractlets (which subtend each flower); heads subglobose to hemispherical, 6-12 mm in diameter; middle cusp of the bractlets elongate, distinctly longer than the lateral cusps | |
14 Leaves with primary veins parallel, with marginal bristles; flowers greenish-white. | |
16 Larger leaves < 1.5 cm wide; marginal bristles in fascicles of 1-3 (-4), those on the lower portion of the leaf usually in fascicles of 2-3 | |
16 Larger leaves > 1.5 cm wide; marginal bristles of leaves solitary | |
18 Heads hemispheric, about as wide as high; [native, seeps, bogs, and wet pine savannas, VA, KY, AR, and OK southwards] | |
19 Bracts of terminal whorl pinnately 3-7-lobed, lobes linear to filiform; mid-culm blades narrowly lanceolate to linear, (5.5-) 6.2-15 (-18)× as long as wide; leaf margins remotely serrate (1-4 teeth per cm at midlength), teeth sharp, irregular, sometimes spinose; stems slender, wiry; [w. Gulf Coastal Plain, or
Inner Coastal Plain of GA]. | |
19 Bracts of terminal whorl 3-(-5)-lobed basally or unlobed, serrate, lanceolate to ovate; mid and upper cauline leaves mostly ovate to lanceolate, (1.5-) 2-3 (-4)× as long as wide; leaf margins serrulate to crenate-dentate (3-8 teeth per cm at mid-length), teeth frequently blunt or rounded; stems stout to slender, erect; [collectively widespread]. | |
22 Bracts of terminal whorl finely serrate, teeth (5-) 7-14 (-19) per side, ovate or elliptic; cauline leaves ovate to elliptic, (1.6-) 2-4.3 (-4.4) cm wide at mid-stem, serrulate (teeth >25 per side); plants robust, the stems stout, the heads commonly 20--50+; [inner Gulf Coastal Plain, Sedimentary Appalachians, and
Piedmont] | |
22 Bracts of terminal whorl 3-lobed (or coarsely toothed), the terminal lobe with 1-3 (-6) additional teeth per side, lanceolate to linear; cauline leaves mostly lanceolate or narrowly elliptic-ovate, (0.7-) 0.9-1.8 (-2.1) cm wide at mid-stem, serrate or crenate-serrate (teeth (6-) 9-22 (-26) per side, rarely more in
E. lanceolatum); plants smaller, the stems slender to moderately stout, the heads usually <25; [bogs and seepage slopes, mostly Coastal Plain, rarely Piedmont and Mountain bogs]. | |
23 Mid-stem blades deltate-lanceolate, (3.4-) 4-6 (-6.7) × as long as wide, regularly serrate with small straight-sided teeth; petioles (1.6-) 1.9-2.9 (-3.6) cm, spreading; [west of the MS River] | |
24 Mid-stem blades sharply serrate, teeth 12-22 (-26) per side; bracts of terminal whorl with irregular long teeth (or weakly 3-parted), teeth (3-) 4-6 (-8) per side (ignore 2º and 3º bracts); leaves and inflorescence branches often lax; [NC, SC; upper Piedmont and low Mountains] | |
24 Mid-stem blades sharply serrate to shallowly crenate-serrate, teeth (6-) 9-12 (-14) per side; bracts of terminal whorl tricuspidate, central lobe with an additional 1-2 (-4) teeth per side (rarely merely coarsely serrate in var. maficolum); leaves and inflorescence branches stiff; [of the Coastal Plain from VA to w. LA, or of the Blue Ridge Mountains of NC and GA]. | |
25 Basal leaves (withering by flowering) flat against soil surface, broadly ovate-elliptic or ovate, obscurely crenate in lower half to subentire; teeth of midstem leaves teeth usually rounded to bluntly acute (edges forming a 45-75º angle, the outer strongly convex); inflorescence branches spreading-ascending; [plants of the Coastal Plain from VA to e. LA, over acidic substrates] | |
25 Basal leaves (withering by flowering) typically ascending, obovate to narrowly ovate-elliptic, often serrate to near apex; teeth of midstem leaves slender, acuminate (edges forming a ~15-30º angle); inflorescence branches erect; [plants of Mountain bogs of NC and GA, usually over mafic substrates] |