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Blue Ridge wakerobin, twisted trillium

dwarf trillium, dwarf wakerobin, least trillium, little trillium

Rhizomes

horizontal, brownish, short, thick, praemorse, not brittle.

horizontal, branching, thin.

Scapes

1–3, round in cross section, 1.5–3 dm, slender to stout, pilose-pubescent, rarely glabrous.

1–2, round in cross section, 0.7–2 dm, slender, becoming taller and more robust after flowering, glabrous.

Bracts

held well above ground, sessile;

blade light silvery or bluish green with strong to faint mottling in darker colors, mottling becoming obscure with age, ovate-lanceolate to broadly ovate, 6.3–7.6 × 3.3–5 cm, larger bracts abaxially pilose-pubescent, margins entire, apex acute.

very short-petiolate, subsessile or sessile;

blade dark green with maroon undertones when young, not mottled, 3–5 major veins from base, oblong to lanceolate-obtuse, 2.5–8+ × 1–3 cm, not glossy, apex obtuse.

Flower

erect, odor strong, of carrion;

sepals displayed above bracts, spreading to ± horizontal position, green, purple markings adaxially, lanceolate-elliptic, 17–40 mm, margins entire, purple, apex acuminate;

petals long-lasting, spreading and carried in ± horizontal position unlike any other sessile trillium, very deep maroon to blackish red, rarely yellow, purple-streaked, with 1–2 spiral twists, narrowly elliptic to lanceolate or linear, narrow, 1.5–3.8 × 0.3–0.6 cm, rarely broader, thick-textured, margins entire, apex sharply acute to rounded, tips incurving slightly;

stamens fully exposed, somewhat stiffly erect, dark purple, 16–24 mm, thick;

filaments dark purple, 2–4 mm, basally dilated;

anthers erect, straight, dark purple, 13–18 mm, thick, dehiscence extrorse;

connectives dark purple, straight, coarse, flat, ± not extended beyond anther sacs;

ovary dark purple, oval, 6-angled, 5–7 mm;

stigmas erect, widely spreading, often strongly recurved or recoiled, distinct, purple, linear, 4–10 mm, slightly thickened basally.

above bracts, erect, odorless to faintly sweet, pedicellate or sessile;

sepals conspicuous, spreading to same plane as petals, dark green with maroon undertones when young, oblong-lanceolate, 15–30 × 5–10 mm, margins entire, apex obtuse to strongly rounded;

petals of short duration, spreading-ascending, exposing stamens and ovary, weakly recurved in distal 1/2, white, aging to deep rosy pink abaxially, veins not engraved but major petal veins clearly visible, oblong to narrowly lanceolate, 1.5–3 × 0.5–1.5 cm, thin-textured, widest above base, margins strongly undulate, quite variable in petal width and degree of undulation between individuals and populations, apex obtuse to weakly acute;

stamens erect-spreading, 8–10 mm;

filaments pinkish purple to white, ± equaling or slightly shorter than anthers, slender;

anthers ± straight, pale lavender or yellow, 3–8(–10) mm, thicker than filaments, dehiscence introrse;

connectives not extended beyond anther sacs;

ovary conspicuous, white, ovoid, obscurely 6-angled, 2.5–8 mm, attachment narrower than ovary;

stigmas confluent with style, greenish white to white, distally 3-lobed, lobes linear (threadlike), long-spreading, 3–12 mm, uniformly thin and threadlike;

pedicel stiffly erect to leaning, 0.5–2 cm, or absent to much reduced.

Fruits

baccate, purple, odorless, ovoid, strongly 6-angled, sometimes winged, 2 × 1–1.5 cm, pulpy, moist.

white or pale greenish, ovate, 1–1.5 cm, pulpy, moist but not juicy.

2n

= 10.

= 10.

Trillium stamineum

Trillium pusillum

Phenology Flowering spring (late Mar–mid May).
Habitat Dry, upland woods of deciduous trees, deciduous forest mixed with pines, soil on limestone outcroppings, mesic woods, sandy flats along medium streams, steep wooded slopes, banks of rivers
Elevation 50–200 m (200–700 ft)
Distribution
from FNA
AL; MS; TN
[WildflowerSearch map]
[BONAP county map]
from USDA
sc United States; se United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Trillium pusillum comprises widely disjunct, regional populations, each varying somewhat from the others and variable within itself as well. Some of these populations have been named as varieties or separate species. In the wild, the plants that have been recognized as var. ozarkanum generally grow taller than others and are said to have bracts with five major veins instead of three. Plants attributed to var. texanum, on the other hand, are generally smaller in all parts, with narrower petals, and often revert to a single bract when not flowering. Only var. virginianum is easily distinguished at sight by its “sessile” flower. This variety has received extensive study. P. R. Cabe (1995), in a morphological study including statistical analysis, found variation within and between populations. He felt that his results were inconclusive, and also that some of the variation might be environmentally induced. The variation that he found did not correlate with a geographic pattern, and he suggested treating all Virginia populations as var. virginianum, or simply T. pusillum. In a later study, P. R. Cabe and C. R. Werth (1995), using isozyme evidence, obtained like results, and suggested treating all Virginia populations as a single variety pending further investigation. Until there has been such study, of the Virginia plants as well as the rest of the T. pusillum complex, I choose to retain the fairly distinctive and more or less traditionally known var. virginianum, and include all other populations in a broadly circumscribed var. pusillum.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Flower pedicillate; pedicel usually 0.5–2 cm.
var. pusillum
1. Flower sessile or subsessile; pedicel, if present, 0.1–0.3 cm
var. virginianum
Source FNA vol. 26, p. 115. FNA vol. 26, p. 101.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Trillium
Sibling taxa
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Subordinate taxa
T. pusillum var. pusillum, T. pusillum var. virginianum
Synonyms T. pumilum
Name authority Harbison: Biltmore Bot. Stud. 1: 23. (1901) Michaux: Fl. Bor.-Amer. 1: 215. (1803)
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