FNA: Tradescantia vs. Tradescantia wrightii

Phenology

Flowering spring–fall (May–Sep).

Habitat

Moist canyon stream banks

Distribution

Neotemperate and neotropical

[BONAP county map]

NM; TX; Mexico (Chihuahua, Coahuila)

[BONAP county map]

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).

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

Tradescantia wrightii var. glandulopubescens was described for Mexican plants with glandular-pubescent pedicels and sepals (B. L. Turner 1983), and this variety was listed for Texas (B. L. Turner 1993; S. L. Hatch et al. 1990). All U.S. collections that I have examined, however, including the holotype of T. wrightii, have at least some glandular hairs on these parts. Marshall Johnson believes that this is a valid variety, and I may not have examined typical specimens, but the diagnosis is not differential from the typical variety.

Tradescantia wrightii and T. pinetorum belong to section Tradescantia ser. Tuberosae D. R. Hunt and differ from the species of ser. Virginianae D. R. Hunt (species 1–19) by being geophytes (instead of hemicryptophytes) and in having the hilum much shorter than the seed (instead of ± equal to the seed). Tradescantia wrightii differs from T. pinetorum by its lack of root tubers, its glabrous leaves and internodes, and the absence of lateral inflorescences. The glandular hairs on the pedicels and sepal bases, much shorter than those of T. pinetorum, are easily overlooked.

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

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	T. 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	T. 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	T. 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	T. brevifolia
5. Filaments bearded, ovary densely bearded; flowering February to May	T. 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	T. 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	T. 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	T. spathacea
9. Inflorescences mostly sessile in axils of distal leaves; boat-shaped spathes absent; leaves usually arachnoid-villous; flowers blue to purple	T. 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	T. 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	T. 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	T. edwardsiana
13. Leaves ± glaucous; capsules 6–8 mm	T. 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	T. 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)	T. ohiensis
17. Plants not at all to slightly glaucous; leaves 4–11 cm, straight, forming nearly right angle with stem	T. paludosa
18. Bracts saccate at base, blades reduced, densely, minutely velvety.	T. 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	T. 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	T. virginiana
20. Roots 1–1.5(–2) mm thick; stems usually pilose to hirsute throughout; sepals not inflated; se	T. hirsutiflora
21. Pedicels 0.8–1 cm, glandular-puberulent; sepals 4–6 mm; petals 9–12 mm; hilum much shorter than seed	T. 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	T. 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	T. roseolens
24. Pedicels 2.5–4.5 cm; at least some roots thick and tuberous; Texas	T. pedicellata
25. Stems, leaves completely glabrous; plants glaucous; sepal hairs mainly glandular (also see Tradescantia roseolens).	T. 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	T. reverchonii
27. Stems spreading, diffusely branched, 10–30 cm.	T. subacaulis
28. Plants diffuse, spreading; stems much branched.	T. humilis
28. Plants erect or ascending; stems unbranched or sparsely branched.	→ 29
29. Sepal hairs mainly eglandular, glandular hairs few, inconspicuous	T. 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	T. 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	T. 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	T. hirsuticaulis
32. Stems 2–10 cm; pedicels (2–)4–6 cm; leaves, bracts pilose but not puberulent, margins sparsely ciliate	T. longipes