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1 Involucre 2-3 mm high; plants to 2.5 dm tall; inflorescence of many, small, axillary and terminal clusters overtopped by subtending leaves | |
1 Involucre 4-7 mm high; plants generally well over 2.5 dm tall; inflorescence terminal, usually elongate |
1 Involucre 2-3 mm high; plants 3-15 (-25) cm tall; inflorescence of many, small, axillary and terminal clusters overtopped by subtending leaves | |
1 Involucre 3-7 mm high; plants 15-100 cm tall; inflorescence terminal, elongate, clustered, or corymbiform. | |
4 Involucres 3-4 mm high; bisexual florets 5-10 (corollas red-tipped); cypselas with papilliform hairs | |
5 Stem glandular-pubescent or glandular-puberulent, the hairs at right angles to the stem, the stem surface plainly visible. | |
6 Stems glandular-villous, the stipitate glands (0.1-) 0.3-1.0 mm high, prominently variable in height on any portion of the stem, with a stalk broadened toward the base and about equal the gland width; pistillate florets 83-107, bisexual florets 9-15; leaves mostly oblong-lanceolate, 2.5-7 cm long, 4-20 mm wide, 4-8 times longer than wide; plant 4-10 dm tall | |
6 Stems glandular-puberulent, the stipitate glands 0.1-0.2 mm high, relatively even in height on any portion of the stem, with a filiform stalk of even width and narrower than the gland width; pistillate florets 47-78, bisexual florets (7-) 11-20; leaves linear to linear-lanceolate or linear-oblanceolate, 1.5-5.5 cm long, 1.5-10 mm wide, 6-10 times longer than wide; plant 3-7 dm tall | |
7 Leaves not clasping, 2-10 (-15) mm wide, linear-lanceolate to elliptic or oblanceolate; [collectively widespread]. | |
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1 Receptacle paleate (bearing receptacular bracts which individually subtend at least some of the flowers of the head). | |
2 Involucres absent or vestigial, usually with 0 phyllaries; heads very small, < 6 mm high, < 4 mm wide; annuals, < 4 dm tall; disc corollas hidden or dingy in color; [tribe Gnaphalieae]. | |
2 Involucres present, conspicuous, of many phyllaries; heads larger, 2-20+ mm wide; perennials or coarse annuals, 2-25 dm tall; disc corollas apparent, white, or pink to purplish or reddish. | |
5 Cypselae with 10 ribs; involucre 3.5-12 (-15) mm tall and in diameter; pappus of 35-40 barbellulate bristles; [mainly Coastal Plain; VA south to s. FL, west to e. LA] | |
6 Heads larger, the involucre 6-15 mm high, with 15-40 phyllaries; leaves with conspicuous (at least at 10× magnification) resin dots. | |
7 Stem with punctate glands; peduncles punctate-glandular and also hirsutulous; pappus bristles in 2 series; [of FL peninsula] | |
1 Receptacle epaleate (lacking receptacular bracts individually subtending flowers, but the receptacle sometimes bearing bristles, setae, hairs, or pits with laciniate margins; some taxa lacking paleae on many or most flowers of the head are keyed here as well, as a failsafe). | |
8 Phyllaries in 1-2 series and equal or subequal in length to one another, the phyllaries often coherent/fused (the involucre thus appearing as a cylinder with ribs extending from base to top, except in species in which the phyllaries are radially winged); calyculus (of bracts subtending the phyllaries and differing from them in texture, color, or orientation) present or not; [tribe Senecioneae] | |
10 Plants annual, upright or ascending, not purple-hairy. | |
9 Perennials (robust annuals in Erechtites), 2-30 dm tall; leaves basally disposed and alternate on the stem (except only alternate in Erechtites); disc flowers cream or yellow (rarely pale lavender in Arnoglossum). | |
12 Plants annual, with leaves primarily on the stem; leaves sharply and raggedly toothed or even pinnately lobed; heads disciform (the outer flowers female, the middle bisexual, and the inner functionally male) | |
13 Disc flowers yellow. | |
14 Annuals; leaves not basally disposed, evenly distributed on the stem, the lower stem leaves more-or-less pinnatifid | |
13 Disc flowers cream, white, or greenish white (to pale lavender in some Arnoglossum). | |
15 Phyllaries 7-21, not radially winged; disc flowers 10-55 (-80+); calyculus absent or of 1-9+ bracts. | |
8 Phyllaries in 3-17 series and unequal in length (imbricated); calyculus absent. | |
19 Plants perennial, mat-forming by stolons, with basal rosettes of spatulate leaves, these usually with obvious appressed hairiness on (at least) the lower and (sometimes also) the upper blade surfaces; erect stems (with scattered alternate leaves) 4-45 cm tall; plants usually dioecious (pistillate and staminate heads on separate plants) | |
19 Plants annual, biennial, or perennial, not mat-forming or stoloniferous, erect, the leaves usually lanceolate or linear (spatulate in some species), leaf surface hairiness variable; erect stems (with alternate leaves) 5-80 cm tall; plants hermaphroditic (with heads containing both pistillate and functionally staminate flowers) or dioecious or subdioecious (in Anaphalis). | |
20 Plants annuals (perennials in Omalotheca sylvatica); heads disciform (each bisexual); plants hermaphroditic. | |
21 Leaves oblanceolate, 1.5-4 mm wide, notched at the tip or with a minute apiculus in the notch; pappus bristles persistent, plumose | |
21 Leaves various in shape, the lager > 4 mm wide, acuminate, acute, obtuse or rounded at the tip; pappus readily falling, the bristles barbellate to barbellulate. | |
22 Heads in capitate clusters arrayed in corymbiform or paniculiform arrays; phyllaries white or silvery; pappus bristles distinct, falling individually | |
24 Perennial; phyllaries in 2-3 series; cypselas strigillose; involucre light to dark brown; [waif, in PA] | |
24 Annual; phyllaries in 3-7 series; cypselas papillate or glabrous; involucre white to red-tinged or brown; [widespread in our region] | |
26 Disc corollas yellow, pale yellow, orange, reddish, or brown. | |
27 Phyllaries 5, in one series; phyllaries streaked with elongate glands filled with strong-scented oil | |
29 Erect or ascending annual or perennial, 1-15 dm tall; heads in corymbiform, paniculiform, or racemiform arrays. | |
30 Plants dioecious, either male or female; heads either staminate, with 10-50 flowers, or pistillate, with 20-150 flowers; heads pale yellow to white | |
31 Leaves (at least the larger) toothed or lobed; flowers 5-35 per head; heads in racemiform, paniculiform, or corymbiform arrays, but if corymbiform, irregular. | |
33 Inflorescences in elongate, racemiform to paniculiform arrays; leaves moderately to densely hairy with both glandular and non-glandular hairs | |
26 Disc corollas pink, purple, lavender, blue, or white. | |
34 Phyllaries either spine-tipped, or appendaged with a marginal zone that is strikingly different in color and texture than the phyllary body (except Leuzea); receptacle epaleate, but densely beset with bristles or subulate scales (flattened bristles). | |
35 Phyllaries scarious-margined, neither spine-tipped nor appendaged with dentate or fringed appendages | |
35 Plyllaries either spine-tipped or appendaged. | |
34 Phyllaries not armed, also not appendaged with a marginal zone that is strikingly different in color and texture than the phyllary body. | |
39 Plants dioecious, either male or female; heads either staminate, with 10-50 flowers, or pistillate, with 20-150 flowers; heads pale yellow to white | |
40 Leaf blades linear, lanceolate, or ovate; leaf margin entire, serrulate, or serrate; [collectively common and widespread]. | |
45 All leaves entire (or at most with a few obscure crenations); phyllaries lacking elongate striations, the nerving not apparent. | |
46 Heads borne in spiciform or racemiform arrays (all heads directly attached to a central access of the capitulescence) | |
46 Heads borne in corymbiform, paniculiform, or thyrsiform arrays (at least some heads borne on secondary branches of the capitulescence. | |
47 Heads 3-20 mm tall; cypselas 10-ribbed. | |
48 Heads 3.5-6 mm tall; phyllaries 5-12 in 1-2 (-3) series; [Coastal Plain, NC to FL to e. LA]. | |
49 Stem with punctate glands; peduncles punctate-glandular and also hirsutulous; pappus bristles in 2 series; [of FL peninsula] | |
48 Heads 3-20 mm tall; phyllaries 15-50+ in 3-7 series; [collectively widespread]. | |
50 Heads borne in corymbiform arrays; involucres 6-12 (15) mm tall; receptacles paleate, at least towards the periphery of the receptacle; pappus of 35-40 barbellulate to barbellate bristles; [nearly restricted to the Coastal Plain] | |
50 Heads borne in paniculiform or thyrsiform arrays; involucres 3-20 mm tall; receptacles epaleate; pappus of 12-40 coarsely barbellate, subplumose, or plumose bristles; [widespread in our region] |