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longbract wakerobin, Underwood's trillium

giant purple wakerobin, giant trillium, giant wakerobin, sessile trillium, small-flower trillium

Rhizomes

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

± erect, brownish, somewhat compressed-thickened, superficially bulblike, praemorse, not brittle.

Scapes

1–2, round in cross section, 0.8-2 dm, slender to stout, glabrous.

1–3, green, round in cross section, 2–6.5 dm, robust.

Bracts

usually drooping, often touching ground in early anthesis, sessile;

blade pale silvery green, strongly mottled in 3 or more shades of dark green and bronze, sometimes maroon, mottling becoming obscure with age, ovate-lanceolate to obovate, 6.5–12 × 5–7.8 cm, margins of distal 1/3 straight from rounded base to apex, apex acuminate.

held well above ground, sessile (narrowing of bract blade may give bract subsessile appearance);

blade densely to weakly mottled in dark brownish green, mottling becoming more obscure to absent as bract matures, broadly ovate, 7–17.6 × 7.4–17.7 cm, not glossy, apex obtuse-rounded.

Flower

erect, odor fetid, especially when first open;

sepals displayed above bracts, spreading, green or purple on adaxial surface, lanceolate, 4.5–5 × 8–12 mm, margins entire, flat, apex rounded-acute;

petals long-lasting, erect-spreading, ± connivent, ± concealing stamens and ovary or at least partially obscuring stamens, tips ± incurved, dark maroon-red, or purplish red, brownish maroon, or yellowish green, not spirally twisted, oblanceolate to elliptic, 3–5.5+ × 1–1.5 cm, usually 3–4 times longer than wide, thick-textured, margins entire, apex acute;

stamens ± erect to weakly incurved, 14–17 mm;

filaments purple, 1–2 mm;

anthers 8–15 mm, thick, dehiscence latrorse;

connectives brown-purple, straight, extended 1–2 mm beyond anther sacs, apex somewhat acute;

ovary purple, ellipsoid, 6-angled, 6.3–11 mm;

stigmas erect, abruptly recurved upon ovary, distinct, purplish, linear, 1.5–5 mm, slightly thickened basally, fleshy.

erect, odor roselike, spicy;

sepals spreading-ascending above bracts, green, lanceolate, 35–65 × 7–12 mm, margins entire, flat, apex obtusely rounded;

petals long-lasting, erect, connivent, ± concealing stamens and ovary, yellow, bronze, maroon, brown, deep purple, reddish brown, pink, dark purplish red, purplish bronze, rarely greenish white, not spirally twisted, veins not engraved, oblanceolate to obovate, 6.5–10 × 1.5–2.5 cm, thick-textured, base cuneate, margins entire, apex variably acute to almost truncate, erose;

stamens erect, purplish, 17–26 mm;

filaments purple, ca. 4 mm, widest at base, much shorter than anther sacs;

anthers erect, straight, ± purple-brown, 13–22 mm, dehiscence introrse;

connectives purple, straight, extended ca. 1–1.5 mm beyond anther sacs;

ovary purple, ovoid, 6-angled, 6–12 mm;

stigmas small, divergent or erect, distinct, purple, subulate, 4–8 mm, not fleshy.

Fruits

baccate, purple-black to dull greenish maroon, odorless, ovoid to obovoid, 6-angled (-ridged), 0.7–1 cm diam., pulpy, not juicy.

red-purple, fragrance not reported, ovoid, obscurely 6-angled, 2.5–3 cm, pulpy, juicy.

2n

= 10.

Trillium underwoodii

Trillium chloropetalum

Phenology Flowering mid winter–spring (late Feb–mid Apr).
Habitat Rich to dryish deciduous forests of mature or second-growth timber, dominated by oaks or with beech-oaks, occasionally with scattered pines present, flat ground along streams where soil can be fairly moist, rich clay or sand
Elevation 100–200 m (300–700 ft)
Distribution
from FNA
AL; FL; GA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
Discussion

Trillium underwoodii can cause considerable confusion for the beginning student of the genus. In some ways it closely resembles a small-statured T. cuneatum. As T. underwoodii continues to expand after flowering, it may become somewhat taller and less “ground hugging,” and it then appears similar to a smaller plant of T. decipiens, which grows in parts of the same range, especially when its bracts do not touch the ground at anthesis. It also has vague similarities to T. reliquum, with which it grows sympatrically in parts of its range. Care should be taken to observe the details of floral structure accurately.

Distribution of Trillium underwoodii is much more restricted than that given by J. K. Small (1933), who indicated a range extending from Alabama to North Carolina and Arkansas.

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

Varieties 2 (2 in the flora).

J. D. Freeman (1975) considered that Trillium chloropetalum differs from T. albidum in having introrse (not latrorse) anther sacs, and that the purple pigments present on anther and ovary tissue here are absent in T. albidum. In some places, hybridization between the two certainly has occurred, and a complete range of intergrades exists.

This species merits further study. The following varieties are only weakly differentiated and perhaps ought to be dropped.

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

Key
1. Petal tissue always with yellow pigments, often present with other pigments; petals yellow, greenish yellow, greenish purple, or bronze-green or brown.
var. chloropetalum
1. Petal tissue lacking yellow pigments; petals purple, reddish purple, garnet red, pink, or greenish white.
var. giganteum
Source FNA vol. 26, p. 116. FNA vol. 26.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Phyllantherum
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. stamineum, T. sulcatum, T. undulatum, T. vaseyi, T. viride, T. viridescens
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, 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. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Subordinate taxa
T. chloropetalum var. chloropetalum, T. chloropetalum var. giganteum
Synonyms T. sessile var. chloropetalum, T. giganteum var. chloropetalum
Name authority Small: Bull. Torrey Bot. Club 24: 172. (1897) (Torrey) Howell: Fl. N.W. Amer., 661. (1902)
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