Flora of the Southeastern United States
2022 Edition

Colors

Data mode

Key to Marshallia

1 Leaves not basally disposed, the leaves all about the same size; plants glabrous throughout; plants colonial by persistent rhizomes; internodes 10-25 (and leaves 2-5× as long as wide)
1 Leaves basally disposed, either all of the leaves below the midpoint of the stem, or the upper leaves markedly smaller than the lower stem and basal leaves (the basal leaves sometimes withered); plants pubescent at least below the heads; plants producing lateral offsets which are separated from the parent in less than a year; internodes 1-12 (and leaves 3-15× as long as wide) or 10-35 (and leaves 8-20× as long as wide).
..2 Phyllaries with acuminate-subulate tips; paleae (receptacular bracts, interspersed with the flowers) with acuminate-subulate tips; plants usually with 2 or more heads; flowering late Jul-mid Oct.
....3 Lower stem leaves (and basal leaves) spreading, oblanceolate or spatulate, with rounded or obtuse apices, relatively thin in texture, the 2 lateral nerves (parallel to the midnerve) often obscure; caudex lacking fibrous remnants of the previous year's leaves; phyllaries thin, linear-subulate, abruptly narrowing to the next series; [e. GA southward and westward; disjunct in Eastern Highland Rim of TN]
....3 Lower stem leaves (and basal leaves) erect, narrowly lanceolate to linear-lanceolate, with attenuate or long-acuminate apices, relatively thick in texture, the 2-4 lateral nerves (parallel to the midnerve) prominent; caudex with fibrous remnants of the previous year's leaves (if not burned off); phyllaries thick, ovate-attenuate, gradually narrowing to the next series; [NC, SC, and extreme e. GA]
..2 Phyllaries with rounded to acute apices; paleae (receptacular bracts, interspersed with the flowers) slightly to strongly broadened or clavate-thickened just below the acute to obtuse apex; plants with 1 head (or more in M. mohrii and M. ramosa); flowering in late Apr-Jul.
......4 Head solitary.
........5 Leafy portion of the stem 0-20 (-30) cm long, the naked peduncle 1.5-10× (or more) as long as the leafy portion of the stem; stem leaves (if present) not reduced upward, the uppermost > 1/2 as long and wide as the largest leaves on the plant; basal leaves obovate to oblanceolate, the apex obtuse to rounded (often emarginate); outer well-developed phyllaries with obtuse to rounded apex, with or without resin glands; corollas white to very pale pink; plants flowering late Apr-May (-early Jun).
..........6 Outer phyllaries lanceolate, apices conspicuously tapered and apiculate; [se. TX, w. LA, e. OK, se. KS, nw. AR, and sw. MO]
..........6 Outer phyllaries oblong-obovate, apices conspicuously rounded (though often apiculate); [s. VA, NC, SC, GA, AL, and e. TN].
............7 Plant with 3-10 leaves on the lower stem, extending (5-) 8-20 (-30) cm up the stem; pappus scales (0.5-) 0.7-1.2 (1.5) mm long; plant (2-) 3-5 (-7) dm tall; outer surface of phyllaries and paleae lacking sessile resin glands (rarely with a very few); [of the Piedmont and rarely Coastal Plain from sc. VA southward]
............7 Plant scapose (all of the leaves basal) or nearly scapose, with 1-5 leaves extending 1-5 (-10) cm up the stem; pappus scales (1.0-) 1.5-2.5 (-3.0) mm long; plant (0.5-) 1.5-3.5 (-5.0) dm tall; outer surface of phyllaries and paleae with many sessile resin glands; [of the Coastal Plain and rarely outer Piedmont from NC southward]
........5 Leafy portion of the stem 23-50 cm long, the naked peduncle 0.4-1.2× as long as the leafy portion of the stem; stem leaves reduced upward, the uppermost < 1/3 as long and wide as the largest leaves on the plant; basal leaves obovate to oblanceolate, the apex obtuse to acute or acuminate; outer well-developed phyllaries with acute to obtuse apex, the outer surface with abundant resin glands; corollas medium pink; plants flowering late Jun-Jul.
..............8 Basal and lower cauline leaves (8-) 15-25 (-32) cm long (including the petiole), (3-) 7-12 (-15) mm wide, averaging about 10× as long as wide (including the petiole), the apex acute to acuminate; phyllaries with abundant resin glands; pappus scales 1.0-1.3 mm long; plants (4-) 6-9 (-10) dm tall; achenes with copious resin-dots between the ridges; [of the Piedmont of nc. NC and sc. VA]
..............8 Basal and lower cauline leaves (2-) 3-13 (-20) cm long (including the petiole), (5-) 10-20 (-30) mm wide, averaging about 6× as long as wide (including the petiole), the apex obtuse to rounded; phyllaries with sparse resin glands; pappus scales 1.5-2.2 mm long; plants (2-) 3-5 (-8.5) dm tall; achenes with absent or scattered resin-dots between the ridges; [of the Mountains of sw. PA, WV, e. KY, e. TN and sw. NC].
................9 Cypselas 4.0-5.5 mm long, medial cypsela teeth 2.0-2.7 mm long; [dry hillsides?, presumably extinct from sw. NC]
................9 Cypselas 2.3-3.5 mm long, medial cypsela teeth 0.9-2.0 mm long; [scour prairies along rivers, sw. PA, WV, e. KY, and e. TN]
......4 Heads 2-10 (-20) (rarely solitary on depauperate plants).
..................10 Leaves 6-10 cm long, 8-23 mm wide, mostly 3-10× as long as wide; heads 2-5 (-10), 22-37 mm in diameter; [sandstone, limestone, and dolostone glades of nw. GA and c. AL]
..................10 Leaves 8-20 cm long, 2-7 (-10) mm wide, mostly > 15× as long as wide; heads (2-) 4-10 (-20), 10-25 mm in diameter; [Altamaha Grit glades, pinelands, and ultramafic outcrop barrens of e. GA and Panhandle FL]
....................11 Heads (2-) 4-10 (-20), 10-25 mm in diameter; phyllaries to 7 (-8) mm long; [Altamaha Grit glades, pinelands, and ultramafic outcrop barrens of e. GA and Panhandle FL]
....................11 Heads (1-) 2-5 (-6), 20-32 mm in diameter; phyllaries to ca. 10 mm long; [limestone hillsides, cobble bars, and rocky slopes, of c. TX, wc. AR, and sc MO].
......................12 Proximal leaves broad and well-spaced, second proximal-most node usually > 3.0 cm long; [wc. AR and sc. MO]
......................12 Proximal leaves narrow and congested, second proximal-most node usually < 3.0 cm long; [s. MO, AR, and OK south to nw. LA and s. TX].