Sabbatical Leave 
Interterm and Spring Terms 2002

The Genus Trillium (Liliaceae) in Virginia

This portion of the Web Site is dedicated to Dr. Paul C. Bailey, my college mentor, who is a retired professor and Dean from Birmingham Southern College

My paper on Trillium in Virginia has been published, and can be accessed here.


Introduction Taxonomic Key
What is a Trillium? Species Descriptions
Trilliums and the Virginia Flora Project Chromosome Numbers
Materials and Methods Literature Cited


What is being shared here is the process of what a "flora" is to be, from the standpoint of one group of plants.  Whatever construct shared here pretty much makes up the components of a flora.  I know that this is more a matter of opinion, but still what is shared here is a composite of how I have done "flora" studies over the past 32 years in Virginia.  

This information came out of a sabbatical leave I took from Bridgewater College in the Interterm and Spring Term of 2002.  It was my last sabbatical.  It was supported by the Mednick Foundation and the Jopson Endowment fund.

The purpose of this sabbatical was to work with the Trilliums of Virginia.  Trilliums are otherwise known as "wake-robins."   They are a group of plants which can be taxonomically difficult.  I mapped the distribution of these species around the state using data from herbarium specimens and field work in Virginia.  I wrote the taxonomic key for identification, composed the species descriptions, and determined the chromosome numbers.  This work is to be published in the March 2005 issue of Castanea, the journal of the Southern Appalachian Botanical Club. There are plans to write a Virginia Flora for the entire state, and this work with Trillium will hopefully be a contribution to that effort.

What is a Trillium?

Trilliums are members of the lily family (Liliaceae).  They are characterized by a whorl of three broad leaves with netted venation and three showy petals.   The flower which sits above these leaves is solitary.  There are three green sepals; and three colored petals.  There are 6 stamens and the fruit is a three-celled berry.  The picture to the right is of Trillium sessile L.  This picture was taken from my backyard collection.  This is a common species in Virginia.  

Trilliums and the Virginia Flora Project

As per my comments on the Virginia Flora Project within this Web Site, the purpose of my work was to contribute to that study through this work with Trilliums.  What is a flora?  It normally is a manual written in a way that can be used by interested botanists, both amateur and professional,  in order to identify the flora of their region.  The advantages of a flora are important from the standpoint of conservation, as well as contributing to the basic botanical knowledge about a region.  Typically floras apply to specific states, while some refer to larger regions, such as the Northeastern United States, etc. 

A flora normally contains (1) a taxonomic key; (2) species descriptions; (3) distribution maps; (4) comments on conservation and economic importance; and (5) either good drawings or pictures.  In the past some of the state manuals also included Chromosome Number data.  This was true for the flora of the Carolinas, as well as the Flora of Utah.  Chromosome number data are extremely important genetic information.  These data provide us with predictions on the success of hybridization, and the phenomenon of polyploidy, both of which has been known to occur  in plants.  Very often in the plant kingdom you cannot discuss the taxonomy of a group unless you speak to chromosome number and morphology.

The taxonomic key is designed to cause one to look at a particular morphological character which is defined in one of two ways.  One of these two definitions are chosen, and this takes you further into the key, which consists of additional "paired" definitions.   It does require a fair amount of botanical knowledge to understand the terms.  Amateurs can handle this as a chore at first, but it becomes easy because once the terms are learned, the taxonomic key becomes easy to use.  Species descriptions ought to be taken from field and herbarium studies, although composing information from other published sources is permissible when the species you are working with is rare or endangered.  Distribution maps of species in a region are essential.  The best way to present this is in the form of maps that outline the region by counties, etc.  In Virginia, which has almost 100 counties, this is a formidable task.  We are blessed with excellent maps of the state flora because of the work of Alton Harvill and his associates (Harvill et al. 1992).  In spite of these available maps, it is best to represent these data specifically within counties when possible.  I did this both in my studies of Virginia Aster (Hill 1980), Sisyrinchium (Hill 1984b), and the Fumariaceae (Hill 1992).  Drawings or pictures are very helpful.  None of my papers have included those kinds of representations.  We do have, however, some excellent pictorial sources on the Virginia flora. These would be the four books put out by Oscar Gupton and Fred Swope on (1) Wildflowers of the Shenandoah Valley and Blue Ridge Mountains (Gupton and Swope 1979); (2) Wildflowers of Tidewater Virginia (Gupton and Swope 1982); (3) Fall flowers of the Blue Ridge and Great Smokey Mountains (Gupton and Swope (1987)  and (4) Trees and Shrubs of Virginia (Gupton and Swope 1981).  And finally, there is the matter of chromosome number data.  I have had an interest in this for some time. It has been agreed that I would put together the chromosome numbers of the Virginia Flora for the Virginia Flora Manual Project.  I have included these data in all of my papers cited above, and including others (Hill, 1995a; 1995b; 1992; 1989; 1987; 1986; 1985a; 1985b; 1984a; 1984b; 1983a; 1983b; 1983c; 1982; and 1978).

Materials and Methods


The sabbatical officially began on 11 December, 2001 with a visit to the Herbarium at Longwood University.  With the assistance of David Buckalew of the Department of Natural Sciences, I was able to secure the Trilliums collected in Virginia by Dr. Harvill and others.  The data on the Herbarium sheets provide me with geographic information in the construction of maps for each of the ten species. Specimens have been borrowed from Lynchburg College, The College of William and Mary, Virginia Polytechnic Institute and State University, The University of Tennessee, West Virginia University, Harvard University, the National Arboretum, George Mason University, and the University of North Carolina at Chapel Hill.   Information on these Herbaria are found in Index Herbariorum.  This is the online and hardcopy source which keeps all of the Herbaria of the World in touch with each other.

The data obtained from a study of these specimens helped to write the key, describe each species, map the species in the state, and determine potential collecting sites for Trillium.  Several sites were visited in Spring of 2002 with follow-ups in Spring of 2003 and 2004.

The study of chromosome numbers will involve standard techniques which are found on this site.  For details, click here.  To view how the lab is set up for this particular work, click here.  I have since discovered a working  technique for the study of Trillium chromosomes in mitosis.  It involves the use of colchicine as a mitotic inhibitor.  The stain used is the Fuelgen Stain, which is specific for DNA.  I have obtained excellent plates of chromosomes for drawing, and it looks like I might be able to karyotype all ten species.  The chromosome numbers for all ten species collected was 2n = 10.  As you peruse the species descriptions, you will see reference to the chromosome number and morphology of each species, as well as discussions comparing my work with others who have also obtained results on chromosome number and morphology.  I am using a nomenclatural system for the chromosomes according to that suggested by Huskins and Smith (1935).  The chromosomes are designated A through E, with A = the most acrocentric of the five pairs, and E = the most metacentric of the five pairs.  While some authors also cite these workers for the nomenclature used in Trillium chromosomes, they have reversed the order of naming to A = the most metacentric chromosome down to E = the most acrocentric chromosome.  This has been confusing when comparing data in the literature.

Taxonomic Key

Taxonomic keys are not always the best vehicle leading to the identification of a plant.  Very often the characters chosen are not that easily seen by the typical observer in the field, and there are other characters which are only available for study in certain seasons.  The best approach is to become very familiar with the populations and study them in some detail.  A key which has been field-tested is a key which ought to work for the person using it.  The key I am submitting below is a "key in progress."  Over time, I will probably include other keys based on characters other than the ones mentioned below.  Eventually the finished key will be shared with colleagues to see if it will work.


TRILLIUM LINNAEUS, Sp. Pl. 1:339.  1753; Gen. Pl. ed. 5, 158.  1754

Perennial scapose herbs with simple stems from short, stocky, horizontal rhizomes bearing a whorl of 3 net-veined, green or mottled, ovate-obovate or elliptical bracts (leaves), petiolate or sessile, flower solitary.  Flowers perfect, sessile or pedicellate; sepals 3, alternating with the leaves, green, reddish or purplish; petals 3 (rarely 4-8), white, red, maroon, purple, pink, yellow or green, ovate or obovate to linear; stamens 6, anthers linear on short filaments; ovary superior, 3-6 lobed or winged, red, white or pink, stigmas 3, sessile or style very short.  Fruit a berrylike capsule, many seeded, globose or ovoid. 

A Key to the genus Trillium in Virginia

1a.  Ovary 3-angled, lobed or winged……………………………………………..…….   2


1b.  Ovary 6-angled, lobed or winged…………………………………………………..   4


       2a.  Bracts sessile; flowers sessile or pedicellate up to 3 cm…….………  T. pusillum


       2b.  Bracts with petioles 5-10 mm; flowers not sessile….………………………….   3


3a.  Bracts up to 5 cm long, obtuse to subacute…………………………..…….    T. nivale


3b.  Bracts more than 5 cm long, ovate to long-acuminate……………..….   T. undulatum


       4a.  Flowers sessile…….….………….………………………..…………………     5


       4b.  Flowers not sessile….….……………………………………………...……..      6


5a.  Petals typically maroon, anther connectives purplish-brown, projecting 2-5 mm


       beyond anther sacs………………………………………………………..    T. sessile


5b.  Petals typically yellow-green, anther connectives green, projecting only


       slightly beyond anther sacs…………………………………….………….    T. luteum


       6a.  Stigma erect or nearly so, slender, of uniform diameter….…….  T. grandiflorum 


       6b. Stigma recurved, stout, tapering distally……………………………………..      7


7a.  Filament scarcely a fourth as long as the anther, 2 mm or less…………..    T. flexipes


7b.  Filament mostly more than fourth as long as the anther, 2 mm or more………...       8


       8a.  Flower on a short, recurved pedicel hidden beneath the bracts;

              anther 3-7 mm long…………………….…………………………    T. cernuum


       8b.  Flower held above the bracts on an erect or declined pedicel;

              anthers 5-12 mm long……………………………………………………….    9


9a.  Flowers cup-shaped, gaping; petals ascending below, recurved, spreading above;

       pedicels declined or flexed, sepals less than half pedicel length…….    T. sulcatum


9b.  Flowers wide open, petals spreading from the base; pedicels erect,

       sepals more than half the pedicel length………………………………    T. erectum


Species Descriptions

Trillium pusillum Michaux. Fl. Bor.-Amer. 1:215.  1803.  Dwarf trillium, early trillium.  T. pusillum Michx. var. virginianum Fernald.  Rhodora 45:  397, plate 773, Figs. 1,2. 1943.  T. pusillum Michx. var. monticulum Bodkin & reveal. Brittonia 34:  142, Fig. 1. 1982.  Rhizomes white, horizontal to erect, up to 10 mm thick, 306 cm long.  Scapes 1-2, 1-2 dm high; glabrous.  Bracts sessile or nearly so, horizontal to drooping distally, 3-5 veined, not mottled, 3-8.5 cm long, 1-2.5 cm wide, lance-elliptic or lance-ovate, obtuse.  Flower above bracts, pedicel 0.5-2.5 cm long, ascending.  Petals white, aging to pink, and then to a pale purple, 1.5-3.5 cm long, 4-10 mm wide, undulate, nearly equal to or slightly longer than the sepals, linear-elliptic to linear.  Stamens 5-10 mm long, filaments broadened at the base, about as long as the yellow anthers.  Ovary white, obtusely 3- angled with white stigmas spreading-ascending.  Fruit about 1 cm long, ovoid or ellipsoid, greenish white. (2N = 10).  late March - late April.  In the Coastal Plain, the habitat is very often an open or shaded swamp.  In western Virginia the habitats vary from dense mixed deciduous forest of Quercus, Hamamelis and Rhododendron sp. (Elliot Knob - Augusta County) to a more open forest at Flagpole Knob (Rockingham County) of Pinus rigida Miller, Pieris floribunda (Sims) B & H, Quercus rubra L., and Kalmia latifolia L. with the trillium scattered under the shade of these plants in haircap moss (Polytrichum).  The distribution of this species in Virginia has led to some interesting interpretations.  It is called Trillium pusillum Michaux in Harvill, et al (1992).  The better-known coastal plain populations were named Trillium pusillum var. virginianum by Fernald (1943).  A western mountain population discovered by Roe (1978), which was then followed by other discoveries in that region (Bodkin and Reveal 1983) was named T. pusillum var. monticulum by Bodkin and Reveal (1982).  Evidence has been presented against this determination (Cabe and Werth 1995a, 1995b).  A morphometric study of the entire Trillium pusillum complex over the southeastern United States (Timmerman-Erskine et al 2002a) produced a similar conclusion to Cabe and Werth that Trillium pusillum is a highly variable species that doesn't warrant varietal designations, although Trillium pusillum var. texanum was elevated to Trillium texanum Barkley (Timmerman-Erskine et al 2002b).  Preliminary data from ITS sequences of the proposed T. pusillum varieties show insufficient variation for their recognition (Farmer 2003).  A study of chromosome morphology of samples from mountain and coastal plain populations of T. pusillum reveals no differences.  These data agree with the published morphology of a coastal plain population by Baldwin (1949).  The present study of Trillium in Virginia will employ the species name without the varietal designations pending further studies at the biochemical level.   Whitish rhizome up to 10 mm thick, 3-6 cm. long; stem greenish, slender, .5-3dm high; leaves sessile or nearly so, 3-5 veined, not mottled, 3-8.5 cm long, 1-2.5 cm wide, lance-elliptic or lance-ovate, obtuse.  Pedicel .5-3cm long, ascending.  Petals white, aging to pink, and then to a pale purple, 1.5-3.5cm long, 4-10 mm wide, undulate, nearly equal to or slightly longer than the sepals, lanceolate.  Filaments broadened at base, about as long as the anthers, forming stamens 5-10 mm long; ovary white, obtusely 3-angled with white stigmas spreading-ascending.  Berry about 1cm long, ovoid or ellipsoid.  

Trillium nivale Riddel.  Syn. Fl. West. States, 93.  1835.  Snow Trillium.  Rhizomes short, white.  Scapes 1, 8-15 cm high, glabrous.  Bracts petiolate, elliptic to lance-ovate to ovate, 2-5 cm long by 1-3 cm wide.  Flower erect, pedicles 5-20 mm long, recurving below the leaves after pollination, sepals 1-3 cm long, spreading, much shorter than the petals; petals white or white with a pinkish base, elliptic or oblong-elliptic, 2-5 cm long, spreading, margins entire to slightly wavy. Stamens 5-18 mm long, pale yellow anthers equal to or slightly exceeding the white filaments.  Ovary greenish white, obtusely 3-angled; style 0.5-1.5 cm long with spreading tips.  Fruits greenish white, globose to ovate, about 1 cm long. (2N = 10).  Early March-early April.  The single report of this species in Virginia is in Highland County on a limestone bluff overlooking the South Branch of the Potomac River very close to the West Virginia border.  Scattered over this site are Acer saccharum Marshall and Tilia sp.  Nesom and LaDuke (1985) discuss the biology of this species from populations in Ohio, and reports a chromosome number of 2N = 10, but no morphological information is shared about these chromosomes.  The studies revealed that Ohio T. nivale was calciphilic, had a range commensurate with the glaciation events of that region, took 3-4 years before sexual maturation occurred; that about nine months was the gap between meiotic activity and eventual flowering; that seeds matured in three months, and that seeds were disseminated by ants.  Further studies by Bayer, LaDuke and Crawford (1987) of genetic variation in the Ohio populations using izozyme markers revealed a low amount of variation that might have been caused by the founders effect.   This suggestion was based on what they observed about the reproductive biology of the species.  The chromosomes I identified in this trillium are not all that markedly different from the published information of a Kentucky population by Bailey (1958).  The distribution of Trillium nivale reveals that it is rare in Virginia.

Trillium undulatum Willdenow.  Ges. Naturf. Fruende Berlin Neue Schriften 3:422.  1801.  Painted trillium, painted lady.   Rhizome horizontal, brown, 2-7 cm long, 10-15 mm wide.  Scapes 1-several, 1-5 dm tall, glabrous.  Bracts strongly petiolate, 5-20 mm long, blade green-maroon, not mottled, ovate to long-acuminate, 5-20 cm long, 5-15 cm wide.  Flower erect above the bracts, pedicles 1-6 cm long, sepals spreading, red to maroon-green, lanceolate-acuminate, petals 2-5 cm long by 1-2 cm wide, white with conspicuous red to purplish stripes at the base, elliptic to elliptic-lanceolate, sometimes undulate.  Stamens 5-10 mm long, anthers yellow or purple, white filaments similar in length to the purple to maroon anthers.  Ovary white, sometimes pink-tipped, 3-angled, 3-10 mm long.  Fuits bright red, 1-2 cm long.  (2N = 10).    In a study of this species out of Canada, Fukuda (2001) found, using cold-induced heterochromatin banding to compare populations, that there was some variation in banding patterns within the species.  This pattern of variation is similar to an Asian species named Trillium govanianum Wall.  The chromosome morphology of Virginian T. undulatum differs from the published report of Fukuda (2001).  The distribution of this species in Virginia is in the western part of the state at the higher altitudes.

Trillium sessile L.  Sp. Pl. 1:340.  1753.  Toadshade, Toad trillium, sessile trillium.  This species is distinguished by its sessile flowers and mottled leaves.  Rhizome thick (1-2 cm), brownish, stout.  Scapes 1-3, 1-3 dm high.  Bracts mottled, green to blusish green, 7-10 cm long, 2-8 cm broad, oval, obtuse or quickly short-tipped, rounding to sessile base.  Flower erect, sessile, sepals spreading, green, oblanceolate to elliptic, slightly shorter than the petals.  Petals erect, maroon to reddish purple or purple, lance-ovate, 1-4 cm long, 1-2 cm wide, margins entire.  Stamens 10-25 mm, filaments red to purple, anthers gray-purple, thick, connectives projecting 2-5 mm beyond the anther sacs.  Ovary greenish white, 409 mm high; stigmas erect, purple, flesh.  Fruits dark greenish purple, with 6 somewhat wing-like angles. (2N = 10).  The chromosomes of T. sessile are similar in morphology to the reports of Bergstrom and Murell (1973); Bailey (1951, 1958); and Darlington and LaCour 1940.  The distribution of Trillium sessile in Virginia is primarily western, but it can move east.  It can be found at low and high altitudes.

Trillium luteum  (Muhlenberg) Harbison, Biltmore Bot. Stud. 1:21.  1901.  Yellow Trillium Yellow toadshae.  Rhizomes brown, horizontal.  Scapes 1-4, 2-4 dm, stout, glabous.  Bracts sessile, well above ground, mottled, ovate-elliptic, apex acuminate.  Flower erect, sessile, sepals green, widely spreading, oblong-lanceolate, 2-5 cm long, 1 cm wide.  Petals long-lasting, greenish yellow, elliptic-lanceolate, 3-7 cm long, 1-2 cm wide, with a long acuminate apex.  Stamens 10-18 mm long, filaments greenish white, anthers yellow; connectives green, extending slightly or not at all beyond the anthers.  Ovary light green, 4-8 mm high, 6-angled.  Stigmas erect, greenish white.  Fruits reddish purple, ovoid, 3 cm high . (2N = 10).  April to May.  In the one report of this species from Clarke County, the taxon is scattered in clearings along a riverbank in association with Cercis canadensis L., Cornus florida L., and Lindera benzoin (L.) Blume.  This population has been interpreted as a local escape from cultivation.  if this one known population in Virginia is native, then it is significantly disjunct since the hearest native populations are in eastern Tennessee, according to Case (2002), who also reports escapes as far as Michigan.  The chromosomes of T. luteum are quite similar to T. luteum of Bailey (1951).  The chromosomes are also similar to reports of T. viride, which is sometimes is combined with T. viride as a synonym.  The distribution of this taxon in Virginia is based on just one known station.

Trillium grandiflorum (Michaux) Salisbury. Parad. Lond. 1:  plate 1.  1805.  Large White Trillium, White Trillium, White wake robin.  Large-flowered trillium.  This pedunculate taxon with the large showy white flower that turns pink with age is the best known and most abundant of the 10 state Trilliums known to occur in Virginia. Rhizome white, 2-4 cm long, 10-30 mm wide.  Scapes 1-3, 2-5 cm high, green, sometimes purple.  Bracts sessile to subsessile, 8-14 cm long, 4-10 cm wide, not mottled, ovate or rhombic, narrowed from below the middle to a cuneate base, apex acuminate.  Flower erect or somewhat inclined, pedicel 4-8 cm long, sepals spreading green, lanceolate, 2-5 cm long, 10-25 mm wide.  Petals erect basally, 4-6 cm long, 2-4 cm wide, recurving from the middle; white changing to pink and then to varying shades of purple, margins overlapping at the base, often undulate, lanceolate, oblong to obovate.  Stamens 10-25 mm long, filaments white, shorter than the anthers, anthers pale yellow.  Ovary pale green or white, 6-angled, 10-20 mm high; fruit greenish white, 1-1.5 cm high. (2N = 10).  April-June.  Rich deciduous or mixed upland woods, floodplains, riverbanks, roadsides.   A study of chromosomal variation over the geographic range of T. grandiflorum by Fukuda and Grant (1980) revealed a greater amount of variation of the "D" chromosome (as defined by Huskins and Smith, 1935) in southern Appalachian populations while there was less variation in that chromosome in the northern populations of the Great Lakes region.  This is in line with the suggestion by Barksdale (1938) and Serota and Smith (1967) that variation in the genus reaches its broadest expression in the southern Appalachian region.   A chromosomal study was done (Chinnappa, 1982) of the mitotic and meiotic chromosomes of this taxon in relation to the tendency of some to show variegation of white and green patterns in the petals.  He did see meiotic irregularities in those which had the variegation, but he did not see any differences in mitotic chromosome morphology between variegated and non-variegated forms. "B" chromosomes, otherwise known as accessory chromosomes were found in this taxon by Rutishauser (1956) and Fukuda and Grant (1980).  My study of the chromosome morphlogy of T. grandiflorum revealed no differences in comparison to the studies of Darlington and LaCour (1940) and Chinnappa and Morton (1978).  The distribution of Trillium grandiflorum is the densest of all of Virginia trilliums, and is primarily western in the mountains and their slopes.

Trillium flexipes Raf.  Autik. Bot., 133.  1840.  Bent Trillium, declined trillium.  Rhizome ascending to erect, gray.  Scapes 1-several, 2-4 dm high, glabrous.  Bracts sessile; rhombic, 7-16 cm long, 7-16 cm wide.  Flower flexed to face outwardd, pedicel 3-12 cm long.  Sepals green, lanceolate, 1-4 cm long, about equal to the petals, apex acuminate.  Petals creamy white, spreading, lance-ovate to ovate, 2-5 cm long, 1-4 cm wide, with deep veins.  Stamens 1-2 cm long, filaments white, shorter than the creamy white anthers.  ovary white, 0.5-1.5 cm high.  Fruit burgundy to reddish purple, 2-3 cm high. (2N = 10).  April-early June.  Slopes of rich deciduous forrest and floodplains.   The chromosome morphology of Trillium flexipes in Virginia differs from that of a reported specimen of this taxon from Iowa (Bailey, 1958), but only with respect to the B chromosome.  The distribution of T. flexipes is in the extreme southwestern counties of the state.

Trillium cernuum  L.  Sp. Pl. 1:339.  1753.  Nodding Trillium.  Rhizome brown, 3-6 cm long, ascending; up to 3 cm in wide; Scapes 1-several, 2-6 dm high, glabrous.  Bracts sessile to slightly petiolate, not mottled, 3-15 cm long, 8-15 cm wide, broadly shombic-ovate, acuminate.  Flower hidden beneth the bracts, nodding.  Sepals spreading, green, 1-3 cm long, equaling or shorter than the petals.  Petals creamy white or pale pink, 1.5-3 cm long.  Stamens 5-15 mm hjigh, filaments white, not as long as the pale pink to gray anthers.  Ovary white to pinkish, 5-10 mm high.  stigmas recurved at the apex, purplish.  Fruit dark red, 2-3 cm high. (2N = 10).  April-June.  rich, moist deciduous forests.  The chromosome morphology of this taxon is similar to a published report by Bailey (1958) for an Alabama population of this species. T. cernuum is located in the western and northern parts of the state at the higher altitudes.

Trillium sulcatum Patrick.  Brittonia 36: 27, Figs 1-4.  1984.  Barksdale'sTrillium, Southern Red Trillium.  Rhizome horizontal or somewhat erect, brownish, 3-6 cm long.  Scapes 1-5, 3-6 dm high, glabrous.  Bracts subsessile, not mottle, broadly elliptic to obovate, 2-5 cm long, 1-3 cm wide, acuminate.   Flower facing outward at right angle to the pedicel, above the bracts, pedicel 4-10 cm long; perianth gaping, cup-like; sepals spreading, green or entirely purplish maroon, apically sulcate, 1.5-4 cm long, 1-1.5 cm wide.  Petals recurved at the apex, maroon to reddish purple, concealing the ovary from side view, 2-5 cm long, 1-3 cm wide.  Stamens 15-20 mm, filaments purple to white, longer than the anthers, anthers purplish to yellow.  Ovary dark purple, 1.5-2 cm high.  Stigmas purple, recurved. Fruits red, 1-3 cm high. (2N = 10).  April-May.  rich, moist, deciduous woods that are scattered with Tsuga candensis (L.) Carr. and Rhododendron maximum L., more common on north-facing slopes.  Trillium sulcatum was erected as a species out of Trillium erectum by Patrick (1984).  He cites the robust habit, flower profile and sepal/pedicel length as distinguishing characters in T. sulcatum.  A chromosomal study of these two species reveal karyotypes that are differentiated from each other.  Using the chromosome identification protocol of Huskins and Smith (1935), the differentiation is most evident in three of the five chromosome pairs marked as "B", "C" and "D."  Trillium sulcatum chromosomes were shorter than T. erectum chromosomes. Patrick (1984) erected this species of Trillium sulcatum out of a population which included, at least in part, a taxon originally identified as Trillium erectum L. var. sulcatum Barksdale.  This variety is described in Barksdale (1938).   Click here for some pics of this species.  The distribution of T. sulcatum is fairly dense in the southwestern counties of the state at the higher altitudes.

Trillium erectum L.  Sp. Pl. 1: 340.  1753.  Wake robin, red trillium, ill-scented trillium, stinking benjamin.  Rhizome brown, 2-6 cm long, 1-3 cm wide.  Scapes 1-several, green to purplish, 2-6 dm tall, glabrous.  Bracts sessile to short-petiolate, not mottled, 5-20 cm long, 5-20 cm wide, often wider than long, broadly rhombic-ovate, acuminate.  Flowers with a fetid odor, erect, pedicels 1-10 cm long.  Sepals flat, streaked with maroon, lanceolate-acuminate, 2-5 cm long, 0.5-1.5 cm wide; petals maroon or white, lancolate to lance-ovate, 3-6 cm long, 1-3 cm wide, widely spreading from the base.  Stamens 5-15 mm long, filaments white, pink to dark purple; anthers maroon or yellowish; ovary purple to maroon, 5-10 mm high; stigmas purple, recurved.  Fruits maroon to reddish purple, black in populations from the higher altitudes, 1-1.5 cm high. (2N = 10).  early April-May.  rich, moist, deciduous upland woods, riverbanks.   Click here for some pics of this taxon.  The chromosomes of Trillium erectum show morphologies that are similar to other published reports (Chinnappa and Morton, 1978; Huskins and Smith, 1935; and Wilson and Boothroyd (1944).  The distribution of this taxon in the state is in western, and at the higher altitudes.


Chromosome Numbers

   The literature survey for the Chromosome numbers of the Trilliums known to occur in Virginia reveals published numbers for nine of the ten taxa.  The populations which generated these numbers are, for the most part, not in Virginia.I had a chance to work with four of these taxa in the mid 1990's.  The other six hopefully will be studied during the Spring 2002 collecting season.  This is not a complete review.  More data will be added as the literature is searched more completely.  What is found below are data taken from the Chromosome Number series of the Missouri Botanical Garden, the International Association for Plant Taxonomy, and the University of North Carolina at Chapel Hill.  

Because the chromosomes of Trilliums are so large, they have been the object of considerable study.  Three approaches have been attempted:  (1) standard karyotypic analyses (Bailey, 1951; Serota, 1969; Fukuda and Channel 1975; Fukuda and Grant 1980; and Chinnappa 1982); (2) analyses of cold-induced heterochomatin bands along the length of the chromosomes (Darlington and LaCour, 1940; Wilson and Boothroyd, 1944; Bailey, 1952;  Rutishouser, 1956; Bailey, 1958; Bergstrom and Murrell, 1973; and Fukuda, 2001); (3) giesma stain banding techniques (Chinnapa and Morton, 1978; and Caspersson et al, 1968).  The scope of my study deals only with chromosome number.  Comments out of many of these studies pertinent to individual species known to occur in Virginia will be included.

Taxon Number References
Trillium cernuum L. n = 5, 2n = 10 Bailey, 1951; Dyer, 1964
Trillium erectum L. n = 5, 2n = 10
Dyer, 1964
Fukuda, 1987; Serota & Smith, 1967; and Plante, 1995
Trillium flexipes Raf. 2n = 10 Bailey, 1958
Trillium grandiflorum (Michaux) Salisbury n = 5, 2n = 10
Dyer, 1964
Utech, 1980; Wcislo, 1987; Chinnappa 1982; Schweizer 1973; Chinnappa & Morton 1978; Fukuda & Grant 1978; 1980; Serota & Smith 1967; Giles & Wilson, 1956; and Rutischauser 1956
 Trillium nivale Riddell n = 5
2n = 10
Nesom & LaDuke, 1985
Hill, 1995
Trillium pusillum Michaux 2n = 10 Hill, 1995; and Baldwin, 1949.
Trillium sessile  L. n = 5, 2n = 10
Bailey, 1951, Dyer, 1964
Utech, 1980; Hill 1995
 Trillium sulcatum Patrick 2n = 10 Patrick, 1984
 Trillium undulatum Willd. 2n = 10 Love & Love, 1982; Plante 1995
  Trillium luteum (Muhlenberg) Harbison n = 5, 2n = 10
Dyer, 1964
Hill 1995

Literature Cited

Bailey, Paul C.  1951.  A study of the Chromosome morphology of some species of Trillium.  Bull. Torrey Bot. Club 78(4):  324-330.

Bailey, Paul C.  1952. Differential reactivity in six species of Trillium.  Bull. Torr. Bot. Club 79(6):  451-458.

Bailey, Paul C.  1958.  Differential chromosome segments in eight species of Trillium.  Bull. Torr. Bot. Club 85(3):  201-214.

Baldwin, J.T.  1949.  Chromosomes of Trillium pusillum Michx. var. virginianum Fern.  Rhodora 51:368.

Barksdale, Lane.  1938.  The pedicellate species of Trillium found in the southern Appalachians.  Jour Elisha Mitchell Sci. Soc. 54:  271-296.

Bayer, Randell J., John C. LaDuke, and Daniel J. Crawford.  1987.  Isozyme variation in Trillium nivale (Liliaceae).  Can. Jour. Bot.  65:2250-2254.

Bergstrom, Beverly H., and James T. Murrell.  1973.  A comparative study of temperature induced differential staining patterns in Trillium sessile L. Jour. Tenn. Acad. Science 48(3):  87-90.

Bodkin, Norlyn L. and James L. Reveal.  1982.  A new variety of Trillium pusillum (Liliaceae) from the Virginias.  Brittonia 34:  141-143.

Bodkin, Norlyn L. and James L. Reveal.  1983.  A new populations of Trillium pusillum var. monticulum Bodkin and Reveal (Liliaceae).  Castanea 48:  155-157.

Cabe, Paul R and Charles Werth 1995a.  The Trillium pusillum Michaux complex in Virginia.  I.  Morphological investigations.  Castanea 60:1-14.

Cabe, Paul R., and Charles Werth 1995b.  The Trillium pusillum complex in Virginia.  II.  Isozyme evidence.  Castanea 60:  15-29.

Caspersson, T., Farber, S., Foley, G.E., Kudynowski, E.J., Modest, E.J., Simonsson, E., Wagh, V. and Zech, L.  1968.  Chemical differentiation along metaphase chromosomes.  Exp. Cell Res 49:  219-222.

Chinnappa, C.C. and J.K. Morton.  1978.  Heterochromatic banding patterns in two species of Trillium.  Canad. J. Genet. Cytol.  20:475-481.

Chinnappa, C.C.  1982.  Cytology of some variegated forms of Trillium grandiflorum (Liliaceae).  Caryologia 35:  23-32.

Darlington, C.D., and L. LaCour.  1940.  Nucleic acid starvation of chromosomes in Trillium.  Jour. Genetics 40:  185-213.

Dyer, A.F.  1964.  Heterochromatin in American and Japanese species of Trillium I.  Fusion of chromocenters and the distribution of H-segments.  Cytologia 29L  155-170.

Fernald, M.L.  1943.  Virginia botanizing under restrictions.  Rhodora 45:396-397.

Fernald, M.L.  1950.  Gray's Manual of Botany.  American Book Company, Boston.

Freeman, J.C.  1975.  Revisions of Trillium subgenus Phyllantherum (Liliaceae).  Brittonia 27(1):  1-63.

Fukuda, I.  1987.  Chromosome compositions of natural populations of Trillium erectum.  Sci. Rep. Tokyo Woman's Christian Univ. 76-79:  943-961.

Fuduka, I.  2001.  The origin and evolution in Trillium 2.  Chromosome variation of Trillium undulatum in North America.  Cytologia 66:  319-327.

Fukuda, I., and R.B. Channell.  1975.  Distribution and evolutionary significance of chromosome variation in Trillium ovatum.  Evolution 29:  257-266.

Fukuda, I., and W.F. Grant.  1978.  Chromosome compositions of natural populations in Trillium grandiflorum.  Sci. Rep. Tokyo Woman's Christ. Univ. Nos. 45-47:  509-547.

Fukuda, I., and W.F. Grant.  1980.  Chromosome variation and evolution in Trillium grandiflorum.  Canad J. Genet. Cytol.  22:81-91.

Giles, R.A., and G.R. Wilson.  1956.  A cytological and morphological study of two populations of Trillium grandiflorum (Michx.) Salisb.  Cytologia 21:  376-383.

Gupton, Oscar W., and Fred C. Swope.  1979.  Wildflowers of the Shenandoah Valley and Blue Ridge Mountains.  University of Virginia Press, Charlottesville, VA.  208pp.

Gupton, Oscar W., and Fred C. Swope.  1981.  Trees and Shrubs of Virginia.  University of Virginia Press, Charlottesville, VA.  205 pp.

Gupton, Oscar W., and Fred C. Swope.  1982.  Wildflowers of Tidewater, Virginia.  University of Virginia Press, Charlottesville, VA.  208 pp.

Gupton, Oscar W., and Fred C. Swope.  1987.  Fall Wildflowers of the Blue Ridge and Great Smoky Mountains.  University of Virginia Press, Charlottesvill, VA. 208 pp.

Harvill, A.M., Jr., Ted R. Bradley, Charles E. Stevens, Thomas F. Wieboldt, Donna M.E. Ware, Douglas W. Ogle, Gwynn W. Ramsey and Gary P. Fleming.  1992.  Atlas of the Virginia Flora, III.  Virginia Botanical Associates, Farmville, Virginia.

Huskins, C.L., and S.G. Smith 1935.  Meiotic chromosomes in Trillium erectum L.  Ann. Bot.  49:119-150.

Hill, L. M.  1995a.  IOPB Chromosome Number Data 9.  Newslett Int. Organ. Pl. Biostyst. (Zurich) 24:  19-20. 

Hill, L. M.  1995b.  IOPB Chromosome Number Data 10.  Newslett Int. Organ. Pl. Biosyst. (Zurich) 25:8-9.

Hill, L. Michael.  1992.  A floristic and chromosomal study of the Fumariaceae in Virginia.  Castanea 57(4):  273-281.

Hill, L. Michael.  1989.  IOPB Chromosome data I.  In:  K.M. Urbanska, Ed., International Organization of Plant Bioststematicists Newsletter No. 13, issued from the Department of Geobotany, Swiss Federal Institute of Technology, Zurich.

Hill, L. Michael.  1987.  Chromsome Numbers of the Virginia Flora IV:  Gymnosperms and the lower vasculars.  Jeffersonia 18(1):  9-10.

Hill, L. Michael.  1986.  Chromosome Numbers of the Virginia Flora III:  Monocotyledonae.  Jeffersonia 17(2):  24-27.

Hill, L. Michael.  1985a.  Chromosome Numbers of the Virginia Flora I:  Dicotyledonae:  Aceraceae-Geraniaceae.  Jeffersonia 16(1):  6-18.

Hill, L. Michael.  1985b.  Chromsome Numbers of the Virginia Flora II:  Dicotyledonae:  Hypericaceae-Violaceae. Jeffersonia 16(3-4):  36-41.a

Hill, L. Michael.  1984a.  In:  A. Love., Ed., IOPB Chromosome Number Reports LXXXIV.  Taxon 33(3):  536-539.

Hill, L. Michael.  1984b.  A floristic and cytological study of the genus Sisyrinchium in Virginia.  Castanea 49:  62-68.

Hill, L. Michael.  1983a.  Chromosome Numbers of twelve species of Aster (Asteraceae) from Virginia.  Castanea 48: 212-217.

Hill, L. Michael.  1983b.  Chromosome Numbers of some Bermuda plants.  Bermuda Department of Agriculture Bulletin 54(4):  26-28.

Hill, L. Michael.  1983c.  Chromosomal typification of Sisyrinchium bermudiana L. (Iridaceae).  Rhodora 85(842):  258.

Hill, L. Michael.  1982.  In:  A. Love, Ed.  IOPB Chromosome Number reports LXXIV.  Taxon 31(1):  119-128. 

Hill, L. Michael.  1980.  The genus Aster (Asteraceae) in Virginia.  Castanea 45:  104-124.

Hill, L. Michael.  1978.  In:  A. Love, Ed.  IOPB Chromosome Number reports LXII.  Taxon 27(5/6):  519-535.

Love, A., and D. Love.  1982.  In:  IOPB chromosome number reports LXXVII.  Taxon 31:  766-768.

Nesom, G.L., and J. C. LaDuke.  1985.  Biology of Trillium nivale (Liliaceae).  Canad. Jour. of Bot. 63:7-14.

Patrick, T.S.  1984.  Trillium sulcatum (Liliaceae), a new species of the Southern Appalachians.  Brittonia 36:26-36.

Plante, S.  1995.  IOBP Chromosome Number Data 10:  Newslett Int. Organ. Pl. Biostst. (Zurich) 25:9-10.

Rutishauser, A.  1956.  Genetics of fragment chromosomes in Trillium grandiflorum.  Heredity 10:195-204.

Schweizer, D. 1973.  Differential staining of plant chromosomes with giesma.  Chromosoma (Berl). 40:  307-320.

Serota, C.A.  1969.  Karyotypes and morphological variation in the sessile-flowered trilliums of North Carlina.  Can. J. Bot 47:  1223-1232.

Serota, C.A., and B. W. Smith.  1967.  The cytoecology of four species of Trillium from western North Carolina.  Am. Jour. Bot. 54:  169-181.

Timmerman-Erskine, Margaret, Roland R. Dute, and Robert S. Boyd.  2002a.  Morphometric analysis of the Trillium pusillum Michaux complex (Trilliaceae) of the Southeastern United States.  Castanea 67(2):  109-119.  

Timmerman, Erskine, Margaret, Roland R. Dute, and Robert S. Boyd.  2002b.  The Trillium pusillum Michaux complex (Trilliaceae):  Analysis of pollen and leaf epidermal micromorphology.  Journal of the Torrey Botanical Society 129(3):  175-186.  

Utech, F.H.  1980a.  Chromosome Atlas of the vascular plants of western Pennsylvania I.  Ann. Carnegie Mus 49:  265-305.

Wcislo, H.  1987.  Chromosome numbers of certain Canadian Plants.  Acta Biol. Cracov., Ser. Bot. 29:  19-30.

Wilson, G.B., and E. Roger Boothroyd.  1944.  Temperature induced differential contraction in the somatic chromosomes of T. erectum L.  Canad. Jour. Res. 22C:  105-119.