Tradescantia

Herbs, perennial. Roots thin or tuberous. Leaves spirally arranged or 2-ranked; blade sessile or rarely petiolate [petiolate]. Inflorescences terminal or terminal and axillary, pairs of cymes, cymes sessile, umbel-like, contracted, subtended by spathaceous bract; bract similar to leaves or differentiated, margins distinct; bracteoles persistent. Flowers bisexual, radially symmetric; pedicels very short or well developed; sepals distinct (basally connate in T. zebrina), subequal; petals distinct (rarely connate basally), white to pink, blue, or violet, equal, rarely clawed; stamens 6, all fertile, equal; filaments bearded or glabrous; ovary 3-locular, ovules (1–)2 per locule, 1-seriate. Capsules 3-valved, 3-locular. Seeds 2 per locule (1 in T. spathacea); hilum oblong to linear; embryotega abaxial to lateral. x = 6–8, probably others.

Distribution

Neotemperate and neotropical.

Discussion

The species described by E. Anderson and R. E. Woodson Jr. (1935) are narrowly defined and typological. Nevertheless, they are recognizable entities even if some of them may prove eventually unworthy of specific rank. Where specific problems have been recognized, they are noted in the discussions at the end of the species.

Tradescantia species hybridize freely when growing together (E. Anderson and R. E. Woodson Jr. 1935). My observations in the field and garden tend to confirm this. The definite or probable hybrids are listed after the species. The list is almost certainly incomplete. The questionable records are based on uncertain determinations. The record of a possible hybrid between T. ohiensis and Callisia rosea (as Cuthbertia rosea), cited by Anderson and Woodson, is omitted: the specimens appear to be merely gracile plants of T. ohiensis. Some native species are occasionally cultivated, although most garden plants seem to be hybrids of T. virginiana and other species (E. Anderson 1952). They are usually sold as Tradescantia × andersoniana (an invalid name) followed by a cultivar epithet.

Species ca. 70 (30 in the flora).

Selected References

Anderson, E. and R. E. Woodson Jr. 1935. The species of Tradescantia indigenous to the United States. Contr. Arnold Arbor. 9: 1--132.

Anderson, E. and K. Sax. 1936. A cytological monograph of the American species of Tradescantia. Bot. Gaz. 97: 433--476.

Anderson, E. 1954. A field survey of chromosome numbers in the species of Tradescantia closely related to Tradescantia virginiana. Ann. Missouri Bot. Gard. 41: 305--327.

Hunt, D. R. 1980. Sections and series in Tradescantia. American Commelinaceae: IX. Kew Bull. 35: 437--442.

MacRoberts, D. T. 1980. Notes on Tradescantia (Commelinaceae) V. Tradescantia of Louisiana. Bull. Mus. Life Sci. Louisiana State Univ. 4: 1--15.

Sinclair, C. 1967. Studies on the Erect Tradescantias. Ph.D. dissertation. University of Missouri.

Lower Taxa

Tradescantia bracteata, Tradescantia brevifolia, Tradescantia buckleyi, Tradescantia crassifolia, Tradescantia crassula, Tradescantia edwardsiana, Tradescantia ernestiana, Tradescantia fluminensis, Tradescantia gigantea, Tradescantia hirsuticaulis, Tradescantia hirsutiflora, Tradescantia humilis, Tradescantia leiandra, Tradescantia longipes, Tradescantia occidentalis, Tradescantia ohiensis, Tradescantia ozarkana, Tradescantia pallida, Tradescantia paludosa, Tradescantia pedicellata, Tradescantia pinetorum, Tradescantia reverchonii, Tradescantia roseolens, Tradescantia spathacea, Tradescantia subacaulis, Tradescantia subaspera, Tradescantia tharpii, Tradescantia virginiana, Tradescantia wrightii, Tradescantia zebrina

Key

1	Flowers subsessile; petals clawed, claws connate at least basally; stamens epipetalous.	> 2
1	Flowers distinctly pedicellate; petals neither clawed nor connate; stamens free.	> 6
2	Leaves 2-ranked, bases oblique, cuneate; blade usually variegated; sepals connate basally	Tradescantia zebrina
2	Leaves spirally arranged, bases symmetric, rounded to broadly cuneate; blade not variegated; sepals distinct.	> 3
3	Leaves narrowly lanceolate, apex acuminate; stamen filaments glabrous	Tradescantia leiandra
3	Leaves lanceolate-elliptic to oblong-elliptic or ovate, apex obtuse to abruptly acute-apiculate; stamen filaments glabrous or bearded.	> 4
4	Leaves oblong-elliptic to lanceolate-elliptic, mostly 7–15 cm; peduncle (3.5–)4–13 cm; leaves usually purplish violet	Tradescantia pallida
4	Leaves oblong-elliptic to ovate, mostly 3–7 cm; peduncle 1–5(–6) cm; leaves green.	> 5
5	Filaments and ovary glabrous; flowering June to October	Tradescantia brevifolia
5	Filaments bearded, ovary densely bearded; flowering February to May	Tradescantia buckleyi
6	Sprawling to decumbent plants rooting at nodes; leaves lanceolate to lanceolate-elliptic or lanceolate-oblong to ovate-lanceolate or ovate-elliptic.	> 7
6	Erect or ascending plants, rarely rooting at nodes; leaves mostly linear-lanceolate to lanceolate-oblong.	> 8
7	Leaves lanceolate-elliptic to ovate-lanceolate, to 5  2 cm; cyme pairs usually 1–2 per shoot; bracts all or mostly foliaceous, occasionally reduced	Tradescantia fluminensis
7	Leaves lanceolate-oblong to ovate-elliptic, to 10  3.5 cm; cyme pairs 2–4 per shoot; bracts, especially those of axillary inflorescences, usually reduced	Tradescantia crassula
8	Inflorescences all or chiefly axillary.	> 9
8	Inflorescences terminal, commonly terminal and axillary.	> 10
9	Inflorescences pedunculate in axils well proximal to shoot apex, enclosed in boat-shaped spathes; leaves glabrous; flowers white	Tradescantia spathacea
9	Inflorescences mostly sessile in axils of distal leaves; boat-shaped spathes absent; leaves usually arachnoid-villous; flowers blue to purple	Tradescantia crassifolia
10	Distal leaf blades wider than opened, flattened sheaths.	> 11
10	Distal leaf blades equal to or narrower than opened, flattened sheaths.	> 14
11	Pedicels 1–1.7 cm; proximal leaves petiolate; stems frequently flexuous; plants flowering mainly May–Sep	Tradescantia subaspera
11	Pedicels (1.5–)2–3.2 cm; proximal leaves narrowed directly into sheath; stems not flexuous; plants flowering mainly Feb–May.	> 12
12	Sepals 9–16 mm, ± inflated, eglandular-pilose; flowers usually deep blue, purple, or rose-red	Tradescantia ernestiana
12	Sepals 6–12 mm, not inflated, glandular-pilose or mixed glandular- and eglandular-pubescent; flowers usually white or pale pink to pale lavender.	> 13
13	Leaves not glaucous; capsules 8–10 mm	Tradescantia edwardsiana
13	Leaves ± glaucous; capsules 6–8 mm	Tradescantia ozarkana
14	Sepals glabrous or with eglandular hairs only (very rarely a few minute glandular hairs at base).	> 15
14	Sepals pubescent with glandular and often eglandular hairs.	> 21
15	Sepals glabrous (or with apical tuft of eglandular hairs or a few minute glandular hairs at base).	> 16
15	Sepals covered with eglandular hairs.	> 18
16	Stems 5–18 cm; pedicels, sepal bases often with minute glandular hairs; petals 10 mm	Tradescantia wrightii
16	Stems 15–115 cm; pedicels glabrous; sepals glabrous or with apical tuft of eglandular hairs; petals usually 0.8–20 mm.	> 17
17	Plants distinctly glaucous; leaves 5–45 cm, arcuate, forming acute angle with stem (also see Tradescantia occidentalis var. scopulorum)	Tradescantia ohiensis
17	Plants not at all to slightly glaucous; leaves 4–11 cm, straight, forming nearly right angle with stem	Tradescantia paludosa
18	Bracts saccate at base, blades reduced, densely, minutely velvety.	Tradescantia gigantea
18	Bracts not saccate at base, blades well developed, sparsely to densely pilose.	> 19
19	Flowering stems 2–7 cm (elongating to 20 cm in fruit), pilose to villous; sepals purple or rose-colored (rarely pale green), not inflated; rocky prairies	Tradescantia tharpii
19	Flowering stems 5–50 cm, glabrous to pilose or hirsute; sepals various; habitat various but rarely rocky prairies.	> 20
20	Roots (1.5–)2–4 mm thick; stems commonly glabrous proximal to inflorescence; sepals usually ± inflated; ne and Appalachian	Tradescantia virginiana
20	Roots 1–1.5(–2) mm thick; stems usually pilose to hirsute throughout; sepals not inflated; se	Tradescantia hirsutiflora
21	Pedicels 0.8–1 cm, glandular-puberulent; sepals 4–6 mm; petals 9–12 mm; hilum much shorter than seed	Tradescantia pinetorum
21	Pedicels (0.8–)1–6 cm, glandular- or eglandular-pubescent; sepals (4–)6–16 mm; petals (6–)10–19 mm; hilum as long as seed.	> 22
22	Sepals with mostly glandular pubescence.	> 23
22	Sepals with mixture of glandular, eglandular pubescence.	> 25
23	Internodes and leaves glabrous	Tradescantia occidentalis
23	Internodes pubescent (rarely glabrous in Tradescantia roseolens)	> 24
24	Pedicels 1–2.8 cm; roots all thin and fibrous; South Carolina to Florida and Alabama	Tradescantia roseolens
24	Pedicels 2.5–4.5 cm; at least some roots thick and tuberous; Texas	Tradescantia pedicellata
25	Stems, leaves completely glabrous; plants glaucous; sepal hairs mainly glandular (also see Tradescantia roseolens).	Tradescantia occidentalis
25	Stems, leaves usually sparsely to densely pubescent, if glabrous then sepal hairs mainly eglandular; plants usually not glaucous (somewhat glaucous in T. roseolens); sepal hairs various.	> 26
26	Stems densely arachnoid-pubescent; roots thick, brownish-tomentose.	> 27
26	Stems variously pubescent but not arachnoid-pubescent; roots various but not brownish-tomentose.	> 28
27	Stems erect or ascending, unbranched or sparsely branched, 30–105 cm	Tradescantia reverchonii
27	Stems spreading, diffusely branched, 10–30 cm.	Tradescantia subacaulis
28	Plants diffuse, spreading; stems much branched.	Tradescantia humilis
28	Plants erect or ascending; stems unbranched or sparsely branched.	> 29
29	Sepal hairs mainly eglandular, glandular hairs few, inconspicuous	Tradescantia hirsutiflora
29	Sepal hairs mainly glandular or eglandular, glandular hairs numerous, conspicuous.	> 30
30	Sepals puberulent, hairs all less than 1 mm; roots relatively thin, 0.5–1(–2) mm thick	Tradescantia roseolens
30	Sepals pilose-puberulent, longer hairs 1.5–6 mm; roots relatively stout, 1–3 mm thick.	> 31
31	Plants bright green; stems, leaves usually glabrous	Tradescantia bracteata
31	Plants dull green; stems, leaves usually pubescent (rarely glabrescent).	> 32
32	Stems (2–)15–40 cm; pedicels 1.5–3.5 cm; leaves, bracts puberulent, usually sparsely to densely pilose, margins ± densely ciliolate	Tradescantia hirsuticaulis
32	Stems 2–10 cm; pedicels (2–)4–6 cm; leaves, bracts pilose but not puberulent, margins sparsely ciliate	Tradescantia longipes