1984] PATRICK: TRILLIUM 27

long recognized Barksdale's trillium, but it has never been legitimately or precisely described. Some results of their morphological studies are included in the un- published thesis by Bass (1977) and in a summary of gynoecium characters by Ihara and Ihara (1978). Freeman listed it as "T. erectum var. sulcatum" (Kartesz & Kartesz, 1980; USDA, 1982), but this was done (J. D. Freeman, pers. comm.) in deference to my current study of the T. erectum species group.

Trillium sulcatum Patrick, sp. nov. (Figs. 1-4)

T. erectum L. var. sulcatum Barksdale, J. Elisha Mitchell Sci. Soc. 54: 228. 1938; nomen nudum, sine descriptione latina.

Ex affinitate Trillui erecti, T. flexipedis, T. similis et T. vaseyi, a quibus pedicellis longis, floribus ringentibus et minoribus, sepalis et petalis apicem versus sulcatis differt. Folia subsessilia, late elliptica vel obovata, apice acuminata, basi gradatim descrescentia, cuneata. Pedicelli longi, stricti, erecti vel fere horizontales sed supra folia. Flores parvuli, ringentes, deorsum aspicientes. Sepala elliptica, ple- rumque purpureotincta vel non nisi margine purpurea, sulcata et interdum apicem versus introflexa, peranguste acuta vel acuminata, persistentia. Petala ovata, apice acuta, profunde vinacea vel purpurea, interdum alba vel luteola, plerumque non nihil longiora quam sepala et similiter apicem versus saltem in senectute sulcata aut partim recurva. Capsula succulenta, globosa, opace rubra, basi irregulatim dehiscens, apice stigmatibus recurvis, atropurpureis, marcescentibus aucta. Flores leniter suaveolentes, odorem fungi vivi accendentem, non foetidum emittentes.

Perennial, glabrous herbs. Stems erect, (22) 30-40 (53) cm tall. Leaves (8) 10- 15 (19) cm long, (7) 9-14 (20) cm wide, subsessile, broadly elliptic to obovate, the apex acuminate, the base gradually narrowing, cuneate. Pedicels (3) 5-9 (12) cm long, straight, erect to almost horizontal but above the leaves. Flowers rela- tively small, ringent, turned downward. Sepals elliptic, (16) 20-3 5 (42) mm long, (7) 8-15 (16) mm wide, green and generally purple-tinged or purple only at the margin, sulcate and sometimes bent inward apically, narrowly acute to acuminate. Petals ovate, (17) 22-38 (54) mm long, (9) 12-24 (29) mm wide, deeply wine- colored to purple, sometimes white to light yellow, generally not much longer than the sepals and similarly sulcate apically, at least during senescence, or partly recurved. Stamens erect; filaments (2.5) 3-5 (6) mm long, purple to white; anthers (5) 5.5-10.5 (12) mm long, purple to yellowish, somewhat overtopping the ovary. Ovary dark purple to white, globose to flask-shaped, strongly hexagonal in trans- verse section, unilocular. Capsule fleshy, globose, dull red, irregularly dehiscent, the sulcate, purple-tinged sepals persistent at the base, the recurved, deep purple stigmas withering at the apex. Flowers mildly fragrant, the odor resembling a fresh fungus, not fetid. Somatic chromosome number, 2n = 10.

TYPE: UNITED STATES. TENNESSEE: Grundy Co.: rich, bouldery woods at base of N-facing slope near Deer Lick Falls in Layne Cove, elev. ca 420 m, western escarpment Cumberland Plateau, 2 km due N of Monteagle, 21 Apr 1980, Patrick, Perkins & Horn 1122 (HOLOTYPE: TENN; ISOTYPES: BH, GH, NCU, NY, UNA, US).

Representative specimens examined: UNITED STATES. ALABAMA: DeKalb Co.: along stream NE of headquarters, Bucks Pocket State Park, Whetstone & Landers 1939 (NCU); along Little Sauty Creek, Patrick 2980 (TENN). Jackson Co.: by falls on mountain, Paint Rock, Ridings s.n. (VDB). Marshall Co.: above impounded creek, Bucks Pocket, Kral 49639 (VDB). GEORGIA: Dade Co.: right fork of Cloudland Canyon, Cronquist 5286 (GH, NY, US); Sand Mt., Graves 84 (BH). Walker Co.: Grayton Gulf, 9 mi SW of Lafayette, Duncan et al. 13853 (VDB). KENTUCKY: Bell Co.: steep N slope, Pine Mt. State Park, Browne & Browne 4044 (KY). Carter Co.: above creek near KY Hwy 182, Aden Springs, Norton 69 (KY). Casey Co.: N slope, Green River Knob, Mintonville, Murphy 354 (KY); same site, Browne et al. 5142 (MEM). Harlan Co.: Big Black Mt., 6 mi from Lynch, McFarland 4513 (KY). Laurel Co.: along US Hwy 25, 5 mi S of Livingston, Watt s.n. (CONN). Lee Co.: along KY Hwy 52, 3.4 mi E of co. line, Browne & Browne 7088 (MEM). Madison Co.: 2 mi SE of Big Hill near Morrill, Suara s.n. (KY). McCreary Co.: 0.25 mi above Devil's Jump on Big South Fork, Stephens 24 (EKY). Morgan Co.: bank of Oldfield Creek, 10 mi W of West Liberty, Oldfield 48 (KY). Perry Co.: Lynn Fork, Braun 529 (OS). Powell Co.: near Raven Rock, Red River Gorge, Helm s.n. (EKY).

28 BRITTONIA [VOL. 36

i 2 * Z : 5 a 7 a 5 14tt It 1n

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Holtyp of Tiliu uctu(Ptrik ekn on12;TN)

1984] PATRICK: TRILLIUM 29

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FIGS. 2-4. Trillium sulcatum. 2, 3. Flower profiles. Photographed in Cumberland Co., Tennessee, 4 May 1981. Sepals 28-31 mm long. 4. Pollen grain from type collection, diameter 32 Am.

Pulaski Co.: upper mesophytic slope, Cumberland River, Braun 2301 (OS). Rockcastle Co.: S of Livingston, McFarland 4518 (KY). Wayne Co.: below cliffs on Beaver Creek, Monticello, Braun 2840 (GH). Whitley Co.: N slope of Buck Branch, Jellico Creek, Braun 2344 (OS). NORTH CAROLINA: Alleghany Co.: near Twin Oaks, Correll & McDowell 10827 (DUKE); near New River, 2.6 mi N of Amelia, Radford 32655 (NCU, NY). Ashe Co.: near NC Hwy 88, 0.7 mi S of Warrensville, Radford 32781 (FSU, NCU). Caldwell Co.: along Yadkin River, Jackson et al. I (BOON). Surry Co.: Stewart's Creek, 4 mi W of Mt. Airy, Allred 1006 (NCU). Watauga Co.: Road's End, Peterson et al. 10 (BOON). Wilkes Co.: 5 mi SE of Wilkesboro on Hunting Creek, Radford 10085 (CM, NCU). TENNESSEE: Anderson Co.: bluffs below Norris Dam, Sharp 13439 (TENN). Bledsoe Co.: near Low Gap, Shanks et al. 3536 (TENN). Campbell Co.: 10 mi N of LaFollette, Preston s.n. (FLAS). Claiborne Co.: near Tazewell, Talcott 717 (MICH). Coffee Co.: Machine Falls near Short Springs Pumping Station, Horn 4 (TENN). Cumberland Co.: 4 mi W of Ozone, Kral 23776b (FSU, SMU, VDB). DeKalb Co.: along Sink Creek near Center Hill Lake, Patrick 2732 (TENN). Fentress Co.: 1.6 mi W of Jamestown, Kral 42302 (VDB). Franklin Co.: below Green's View, Sasnett & Ramseur 49 (NCU). Grundy Co.: near Monteagle, Svenson 7658 (BH, BKL, MO, MUHW, PH, TENN, WIS). Hamblen Co.: Panther Creek, Hut s.n. (ETSU). Hamilton Co.: Big Falling Water Gulch, McGilliard s.n. (UCHT). Hancock Co.: along Clinch River, E of Kyle's Ford, Sharp et al. 32672 (TENN). Hawkins Co.: Louderback Mt., Wolfe 19206 (TENN). Johnson Co.: Iron Mt., Sharp 1486 (TENN). Knox Co.: Roaring Springs, Underwood 685 (IND, NA, TENN). Lincoln Co.: Teal Hollow, Patrick 1099 (TENN). Marion Co.: along Battle Creek, 5 mi NW of South Pittsburg, Kral 34323 (AUA, TENN, US, VDB). Morgan Co.: near Rugby, Svenson 9345 (BKL, MUHW). Pickett Co.: Flint Fork Cove, Whitten & Noss s.n. (TENN). Putnam Co.: 1.5 mi due NW of Brotherton, Patrick & Simmers 2671 (BH, TENN). Rhea Co.: lower Richland Creek near Dayton, Shanks et al. 4295 (TENN). Roane Co.: along Emory River, Kearney s.n. (OS). Scott Co.: 3.6 mi S of Huntsville, Morton & Bowers 42610 (NY, TENN, VPI). Sequatchie Co.: Suck Creek Gulch, McGilliard & Cross 2 (UCHT). Sullivan Co.: Holston Mt., Sharp et al. 1875 (GA, TENN). VanBuren Co.: near Fall Creek Falls, Iltis 1718 (SMU, TENN). Warren Co.: W side of Nunley Cove, 4.6 mi ESE of Viola, Patrick & Whitten 2612 (BH, TENN, VDB). White Co.: escarpment near Lowry Spring, Shaver s. n. (VDB). VIRGINIA: Carroll Co.: Grassy Creek, Uttal 6987 (VPI, WILLI). Floyd Co.: N slope of Buffalo Mt., Burrell et al. 20 (VPI). Franklin Co.: by VA Hwy 640, Fivemile Mt., Stevens 12911 (FARM). Giles Co.: across New River from Goodwin's Ferry, Kral 14574 (FSU, SMU, VDB), along Pond Drain, Mt. Lake Biological Station, Thorne 17943 (GA, IA). Grayson Co.: along New River, S of Independence, Harvill 16436 (FARM, NCU). Henry Co.: along Smith River, Rt. 57, Bassett, Reed 28182 (Reed Herbarium, Baltimore, Maryland); opposite Philpott, Stevens 13230 (VPI). Lee Co.: W of Pennington Gap, Harvill 34324 (FARM). Patrick Co.: Rock Castle Creek Flats, 3 mi S of Blue Ridge Pkwy on Rt. 8, LUttal 7887 (MASS, QUE, VPI). Pulaski Co.: near Rt. 764 bridge over Big Reed Island Creek, LTttal 6959 (NLU, VPI). Roanoke Co.: Bent Mt., 0.75 mi N of Airpoint P. O., Wood 1140 (PENN), also Wood 3109 (PH). Russell Co.: ca 2 mi S of Rockdell, Mikula 6436 (NCU). Scott Co.: 2 mi E of Stanleytown, Stevens & Harvill 28600 (FARM). Smyth Co.: E side of Interstate 81, 9 mi S of Marion, Ramsey 5175 (LYN, NCU), also Ramsey 5174 (LYN, NCU, VPI). Tazewell Co.: Hutchinson Rock above Burkes Garden, Harvill 12165 (FARM). Washington Co.: E of Damascus, Harvill 16409 (FARM, NCU); White Top Mt., Britton et al. s.n. (CM, G, MU, PH).

30 BRITTONIA [VOL. 3 6

Wise Co.: below High Knob, Harvill 18436 (FARM, NCU). WEST VIRGINIA. Fayette Co.: Walnut Knob, Manns Creek Watershed, New River, Grafton & McGraw s. n. (WVA). McDowell Co.: Anawalt, Music s.n. (WVA). Mercer Co.: along Bluestone River near Roak, Uttal 9652 (NLU); near Oakvale, McNeill s.n. (WVA).

Barksdale's designated type material (Barksdale, 1938) for his "var. sulcatum" is as follows: NORTH CAROLINA: Surry Co.: in deep woods near Roaring Gap, vicinity of Doughton, Thurmond and Elkin, elev. ca 620 m, 27 Apr 1937, Lyons s.n. (FSU, NCU-6 sheets). These specimens are considered typical T. sulcatum and, as all other representative specimens cited herein, serve as paratypes of the new species.

Two petal color forms are described within T. sulcatum, as follows:

TRILLIUM SULCATUM f. SULCATUM

Petals deep maroon to reddish-maroon, sometimes greenish basally on the underside. The predominant color form.

Trillium sulcatum f. albolutescens Patrick, f. nov.

A f. sulcato petalis albis vel luteolis differt.

Petals white to yellowish-white or creamy, often expressed as off-white, also sometimes greenish on the underside. Found sporadically throughout the species range.

TYPE: UNITED STATES. NORTH CAROLINA: Ashe Co.: rich, shady W slopes of The Peak, 16 May 1950, Harper 4167 (HOLOTYPE: MO; ISOTYPES: GH, NY, UNA).

Elaboration of Characters

When Barksdale (1938) described T. sulcatum as a variety of T. erectum, he emphasized its longer pedicels, sulcate-tipped sepals, and conspicuously ringent flowers. As the petals first start to wither, they too become sulcate, that is, widely grooved in profile with upturned lateral halves, the margins and apex inflexed. Some confusion about the sulcate character is evident from the original descrip- tion; Barksdale noted "petals sulcate" in his key, but only "sepals sulcate" in his description. Several other species of Trillium show a degree of marginal or apical upturning or both in sepals. Examples are T. pusillum Michx. var. monticulum Bodkin & Reveal with cymbiform sepals or T. discolor Wray ex Hooker and T. stamineum Harbison with apiculate buds. Sepals of Trillium typically are cym- biform in early anthesis, as they are in bud, and may remain so throughout the season, but usually do not. Nevertheless, because sulcate sepals and sulcate se- nescent petals are distinctive of T. sulcatum, I have retained Barksdale's epithet.

The long pedicel is a more useful feature in the recognition of T. sulcatum. Speaking of collections from the Cumberland Plateau of Tennessee, all of which are now determined as T. sulcatum, Svenson (1941, p. 125) stated that they had ". . . slender stems and elongate erect pedicels, quite different in appearance from the fleshy plant, usually with declinate pedicels, which is common in the Northern States." Although no species in the T. erectum complex has consistently erect or vertical pedicels throughout its range, his mention of long pedicels is noteworthy.

Trillium sulcatum is compared to its closest allies in Table I. Flower fragrance is subjective and is released only by fresh flowers during warm periods. Fragrance is correlated with petal color in each species. Anderson (1934), Barksdale (1938), Voss (1972), and others have shown that fragrance of a species may be stronger in a maroon flower than in its white counterpart, or vice versa; varying with temperature, coloration, and freshness, fragrance does not separate taxa. Flower profile and stamen characters are foremost in distinguishing species. Relative heights of stamen and pistil are unreliable unless several plants are measured; depauperate individuals tend to have normal stamens and greatly reduced ovaries,

19841 PATRICK: TRILLIUM 31

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32 BRITTONIA [VOL. 3 6

and immature plants display extended stigmatic lobes that have not yet become helicoid.

The flower of T. sulcatum is relatively small. Flower size, as expressed by the ratio of sepal to pedicel length, is a character particularly useful in delimiting T. sulcatum. The sepal to pedicel ratios for the other taxa in Table I show little overlap with T. sulcatum. In general, the sepals of Barksdale's trillium are less than half as long as the pedicel, whereas in other members of the species group they are more than half as long. Some of the Kentucky specimens (Reed Her- barium, Baltimore, Maryland) cited by Reed (1962) as "small-flowered" T. erec- tum are referable to T. sulcatum.

Trillium pollen shows considerable variation in exine sculpturing under the SEM. Patrick (1982) concluded that species groups can be delimited by pollen type and that narrowly restricted endemics often have unique exine patterns. Takahashi (1982) provided the first formal categorization of pollen types. He observed some taxa in the T. erectum complex, and I have observed pollen architecture of all the species. Pollen of the complex is granulate. Trillium vaseyi has dimorphic granules, a tight matrix of smaller protuberances through which scattered larger ones are distributed. Pollen of T. flexipes and T. simile consists of a surface of loosely aligned, irregular granules. Pollen of T. erectum and T. sulcatum has clumped, angular granules of similar size and shape (Fig. 4).

A suite of characters is needed to distinguish each species of the T. erectum complex. Measurements, though they quantitatively describe taxa, often do not exclusively delineate them. Ecological factors profoundly modify geophytes such as Trillium. Nutrient availability, moisture, and disturbance (logging, windthrow, fire), among other factors, affect size of floral and vegetative features. Further, although each species has a predominant coloration, the genus is noted for vari- ation in the color of flower parts and consequently for overlap of coloration patterns among and between species. As with measurements, color alone is rarely enough to identify a specimen definitively.

When fully expanded plants with flowers in anthesis are considered, T. sulcatum is most practically distinguished from its closest relatives as follows:

1. Robust habit-stems commonly to 4 dm tall; pedicels usually 6.5 cm long or considerably longer.

2. Flower profile-petals held moderately agape, the flowers thus ringent, out- ward- to downward-facing, often perpendicular to the long, straight pedicel, in profile resembling a long-handled candle snuffer (Figs. 2 & 3).

3. Sepals-less than half the pedicel length in T. sulcatum, longer in other taxa; persistently purple-tinged and apically sulcate.

Distributional Highlights

Trillium sulcatum flourishes in mesic forests with hemlock (Tsuga canadensis), numerous deciduous trees, and scattered rosebay (Rhododendron maximum). It is found in association with many other spring-flowering herbs at the base of north-facing slopes, on escarpments and in sinkholes. In moist pockets along watercourses on the Cumberland Plateau, it may be the only showy liliaceous plant found. Trilliums sympatric over parts of its range are T. cuneatum Raf., T. erectum, T. flexipes, T. grandiflorum (Michx.) Salisb., T. luteum (Muhl.) Harbi- son, and T. recurvatum Beck.

Barksdale's annotated specimens, mostly at NCU, and published remarks (Barksdale, 1938) indicate that he thought T. sulcatum limited to the Blue Ridge Province of northwestern North Carolina, probably extending into the Virginias by way of the New River drainage. Herbarium data and field observations indicate

1984] PATRICK: TRILLIUM 33

FIG. 5. Physiographic distribution of Trillium sulcatum in the southeastern United States.

a considerably wider range. Throughout this discussion, physiographic boundaries are those delimited by Fenneman (1938) and depicted in Figure 5.

Trillium sulcatum is most abundant on the Cumberland Plateau, the southern- most section of the Appalachian Plateaus Province (AP). Several sites are known from the Highland Rim, the southeasternmost section of the Interior Low Plateaus Province (IP). The Ridge and Valley Province (RV) harbors the species in the northeastern part of its range, where it eventually extends across the Blue Ridge Province (BR) into the Piedmont Province (P) to the east and two additional sections of the Appalachian Plateaus Province, the Cumberland Mountains in western Virginia and southeastern Kentucky, and the Alleghany Plateau in south- ern West Virginia.

Although local, the species is widespread from northeastern Alabama and north- western Georgia northward through Tennessee into eastern Kentucky. From Ten- nessee it extends northeastward into Virginia and, by the New River drainage, reaches both West Virginia and North Carolina. The range is shown in Figure 5 in which each dot corresponds to one county record from the list of representative specimens examined. The species is listed as "Threatened" on the official list of Alabama's rare plants (Freeman et al., 1979). Endangerment in other peripheral parts of the range, as in Georgia and West Virginia, can be determined only after additional field searches.

Pedicellate-flowered trilliums abound in the southern Appalachians, especially in the Great Smoky Mountains, but T. sulcatum is absent from this floristically

34 BRITTONIA [VOL. 36

rich area; the center of its distribution lies on the Cumberland Plateau. Freeman (1975, p. 40) points to a more southern Coastal Plain (CP) or Piedmont Plateau center of distribution for some sessile-flowered taxa but suggests the "Appalachian system as a Pleistocene refugium" for pedicellate-flowered taxa. Several lines of evidence suggest that the southern Appalachians are of considerable phytogeo- graphic importance to the T. erectum species group.

Trillium has long been recognized as an element of the Arcto-Tertiary Geoflora (Gray, 1859; Wood, 1972; Samejima, 1976). Supposedly, remnants of the Tertiary flora are most numerous in the species-rich mixed mesophytic forest (Braun, 1950; Delcourt, 1979). The Cumberland Plateau embodies many topographic features that may have sheltered Tertiary relicts. Analysis of present-day vegetation pat- terns reveals that the mixed mesophytic forest is restricted to sheltered coves and north-facing slopes of the Cumberland Plateau (Schmalzer et al., 1978)-precisely the haunts of trilliums such as T. flexipes and T. sulcatum.

Evidence of affinities between American and Asiatic trilliums sheds some light on what taxa (or progenitors) may have been part of the Arcto-Tertiary Geoflora. American Trillium investigated to date, including all members of the T. erectum complex (T. Patrick, unpublished data), are diploid with 2n = 10. The single Asian diploid is T. camschatcense Ker (= T. kamtschaticum Pallas ex Pursh); all other species from Japan to the Himalayan Mountains are allopolyploid (Samejima & Samejima, 1962). Haga and Channell (1982) obtained crossing data substantiating considerable genetic affinity between T. erectum and T. camschatcense. Trillium flexipes, purported to hybridize with T. erectum (Case & Burrows, 1962), bears a striking resemblance to the Asian diploid. Such morphological and genetic ties may indicate the relative primitiveness of these taxa when compared to other American species or Asian polyploids, or, at the least, point to their continuous distribution sometime in the past.

Trillium sulcatum infrequently is sympatric with T. flexipes, a species whose center of distribution is the northwestern Interior Low Plateaus Province. Par- ticularly when sympatry occurs in rich habitats underlain by calcareous shales and limestones, these trilliums give rise to morphological intermediates.

Representative T. flexipes x T. sulcatum examined: TENNESSEE: Campbell Co.: along Hickory Creek, 0.4 mi NNE of Morley, Patrick 2731 (TENN); along US Hwy 25W, 3 mi E of Jellico, Patrick & Whitten 2825 (TENN). Coffee Co.: along Copperas Creek, Horn 65 (TENN). Hamblen Co.: Panther Creek, Hut s.n. (ETSU). Lincoln Co.: near Rowell's Crossroads, Freeman 970b (AUA, TENN, VDB); Teal Hollow, Patrick 1098 (TENN). VIRGINIA: Russell Co.: near summit of Clinch Mt., 4 mi NW of Mendota, Kral & Bass 23869 (VDB).

The apparent affinity between T. sulcatum and T. flexipes, the strong morpho- logical similarity of both to the only extant Asian diploid, and the demonstrable floristic connections between the mixed mesophytic flora, the Arcto-Tertiary Geo- flora, and their present-day range, plausibly suggest that T. sulcatum has a relictual distribution. Besides the Cumberland Plateau, the New River drainage from North Carolina into West Virginia has also been implicated in harboring relicts, or at least in providing an important, ancient migration route (Wieboldt & Bentley, 1982). Further, the absence of T. sulcatum from the Great Smoky Mountains and all other mountain ranges near the southern end of the Blue Ridge Province may be accounted for by prior vast vegetation changes at these relatively high elevations which impeded east-west plant migration (Watts, 1979).

The Delineation of Species in Trillium

Trillium sulcatum is better treated as a species than at any infraspecific rank. It can be distinguished by easily observed morphological characters, even though flower profile and fragrance are more evident in fresh material than in pressed

1984] PATRICK: TRILLIUM 35

specimens. The limitations of dried, pressed plants have hindered recognition of T. sulcatum even as a variety by botanists unfamiliar with field characters. Its distinctive, limited, and probably relictual distribution in combination with strong morphological divergence are compelling reasons for regarding T. sulcatum as a species.

Indisputable affinities, as shown by intergradation, especially in areas of overlap, should be recognized in any taxonomic scheme. Where the ranges of T. flexipes and T. sulcatum come together, some morphological intermediates have been found, suggesting compatibility and infraspecific rank. However, the morpholog- ical similarities between other members of the complex must be considered. In the past, specimens of T. sulcatum have been variously determined as erect- flowered T. vaseyi or long-pedicelled T. erectum. The gross similarity of these three maroon-flowered taxa makes intermediates between them difficult to identify in the absence of controlled garden experiments. On the other hand, when T. sulcatum occurs with the primarily white-flowered T. flexipes, petal color vari- ability increases and this presumably indicates morphological intermediacy. True, intermediates are found in a few scattered sites, but rampant mixing seems limited to peripheral populations in rich mesic habitats.

Such restricted examples of apparent compatibility with T. flexipes and the unknown degree of intergradation with certain other taxa, especially with T. erectum in Kentucky and the Virginias, demonstrate the need for genetic studies. Even should most taxa within the complex prove to be compatible in the exper- imental garden, a realistic nomenclature still could not accommodate several infraspecific taxa within a limited geographical area. Clearly, all of the taxa are readily distinguishable in their natural habitats throughout most of their geo- graphical ranges. The most practical approach is to treat the T. erectum complex as comprising a few morphologically similar but distinctive species with note- worthy (and often confusing) petal color forms. Studies involving garden culture, hybridization, and phytochemistry, some already completed, should further elu- cidate the relationships within this species group and will be reported at a future date, but the taxonomic considerations discussed herein are not likely to be greatly affected by these studies.

Acknowledgments

Joseph L. Collins, A. Murray Evans, Frank F. Fusiak, Bretta E. Perkins, and B. Eugene Wofford provided editorial assistance and persistent encouragement. John D. Freeman critiqued an earlier version and freely shared valuable insights on Trillium. R. B. Channell, Masaaki Ihara, and Kazuko Samejima enlightened the author on several points. William L. Dress assisted with Latin translation; Ronald H. Petersen helped with nomenclature. For sharing locality data and field experiences, I especially wish to thank A. Leon Bates, Dennis D. Horn, Roger W. Riffle, Richard W. Simmers, Jr., and Victor G. Soukup. This study was greatly enhanced by the loan of specimens from the cited herbaria and by the financial assistance given by the Department of Botany, University of Tennessee.

Literature Cited

Anderson, W. A. 1934. Notes on the flora of Tennessee: the genus Trillium. Rhodora 36: 119-128. Barksdale, L. 1938. The pedicellate species of Trillium found in the southern Appalachians. J. Elisha

Mitchell Sci. Soc. 54: 271-296. Bass, J. L., III. 1977. The erectum complex of Trillium L. (Liliaceae) in the southern Appalachians:

comparative quantitative morphology. M.S. Thesis, Vanderbilt University. Braun, E. L. 1950 (reprinted in 1964). Deciduous forests of eastern North America. Hafner Press,

New York.