FNA: Portulacaceae vs. Claytonia

Distribution

Primarily Southern Hemisphere; poorly represented in Eurasia

North America; (including Mexico); Central America (Guatemala); Asia; adventive in Europe and New Zealand A related species; Claytonia joanneana Roemer & Schultes; occurs in the Altai Mountains of Siberia and Mongolia

[BONAP county map]

Discussion

Genera 20–30, species ca. 500 (9 genera, 91 species in the flora).

The eastern New World species of Portulacaceae seem to have a closer relationship with the African species, and the western New World species a closer one with the Australian species, than the two New World groups have with each other to each other.

The outer perianth segments, referred to herein as sepals, are held by some (e.g., T. Eckardt 1976) to be modified bracteoles, the petals then representing the true sepals. However, the traditional interpretation, adopted here and in most North American floras, still finds current support (R. C. Carolin 1987). A comparable situation prevails with respect to the cauline leaves in Claytonia and other genera, which are widely interpreted to be foliaceous bracts (R. C. Carolin 1987); here again, as is appropriate in a descriptive context, the traditional terminology is employed. In Talinopsis and Portulaca, the stipular nature of the nodal or axillary hairs also has been a matter of discussion. The question was revisited by R. Geesink (1969), who denied their stipular origin.

The relationships of the family are not a matter of dispute (A. Cronquist 1981; R. C. Carolin 1987); the same cannot be said for the relationships and delimitations of the genera, which have always been labile. They are, at present, the subject of active research, which has led to the current acceptance of Phemeranthus and Cistanthe. Changes in the generic classification are discussed in the treatments of the genera concerned.

Because of the uncertain relationships, the genera and species are listed alphabetically.

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

Species 26 (25 in the flora).

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

Key

1. Ovary half-inferior to inferior	Portulaca
1. Ovary superior	→ 2
2. Subshrubs; stem nodes pubescent	Talinopsis
2. Herbs; stem nodes glabrous	→ 3
3. Capsule dehiscence circumscissile, valves longitudinally dehiscent from base	→ 4
3. Capsule dehiscence not circumscissile, valves longitudinally dehiscent from apex	→ 5
4. Petals 25-40 mm; seeds strophiolate; nc Washington to extreme sc British Columbia	Cistanthe
4. Petals 4-26 mm (15-35 mm in Lewisia rediviva); seeds estrophiolate; more widespread	Lewisia
5. Stigmas 2; capsule valves 2	Cistanthe
5. Stigmas 1 or 3; capsule valves 2-3	→ 6
6. Sepals mostly deciduous; inflorescences not appearing secund; leaves articulate at base, attachment points round, not clasping; capsule valves wholly or partly deciduous	→ 7
6. Sepals persistent; inflorescences somewhat to markedly secund (at least distally); leaves not articulate at base, attachment points linear, somewhat to markedly clasping; capsule valves not deciduous	→ 8
7. Leaf blades broadly planate, 1-7 cm wide; capsules tardily dehiscent, valves or portions of them sometimes persistent; exocarp and endocarp distinctly differentiated, sometimes separating; seeds minutely tuberculate or striolate, strophiolate, not covered by membrane	Talinum
7. Leaf blades terete or semiterete, 1-3 mm wide, (narrowly planate, 1[-2] cm wide in Phemeranthus aurantiacus); capsules promptly dehiscent, valves deciduous; exocarp and endocarp not evidently differentiated and not separating; seeds smooth, rugulose, or distinctly ridged, estrophiolate, covered by thin, fleshy to chartaceous membrane	Phemeranthus
8. Ovules and seeds (1-)7-40	→ 9
8. Ovules 3 or 6; seeds 1-6	→ 10
9. Leaves and sepals sometimes with elongate, unicellular hairs; sepals distinctly angular or keeled; capsule valves reflexed after dehiscence, margins markedly involute	Calandrinia
9. Leaves and sepals without elongate, unicellular hairs; sepals not distinctly angled or keeled; capsule valves not reflexed after dehiscence, margins not markedly involute	Cistanthe
10. Cauline leaves 2 (rarely 3 in whorl), distinct or partially or completely connate; ovules 3 or 6	Claytonia
10. Cauline leaves more than 2, distinct; ovules 3	Montia

1. Plants annual, sometimes biennial, with minute, tuberous bodies	→ 2
1. Plants perennial, with stolons, rhizomes, tubers, or woody caudices	→ 10
2. Inflorescences with 2-several bracts (rarely only 2); proximalmost bract leaflike, distal bracts leaflike or reduced to membranous scales	→ 3
2. Inflorescence ebracteate or 1-bracteate; bract leaflike	→ 5
3. Flowers 4-8 mm diam.; petals not candy-striped; basal leaf blades rhombic or ovate	C. washingtoniana
3. Flowers 8-20 mm diam.; petals white, candy-striped, or pink; basal leaf blades linear to deltate	→ 4
4. Cauline leaf blades linear; distal bracts reduced to membranous scales; seeds (1-)6	C. arenicola
4. Cauline leaf blades broad; distal bracts leaflike; seeds (1-)3	C. sibirica
5. Flowers 10-15 mm diam.; inflorescences ebracteate	C. saxosa
5. Flowers 2-12 mm diam.; inflorescences 1-bracteate	→ 6
6. Basal leaf blades usually trullate or rhombic to deltate, sometimes spatulate, less than 3 times longer than wide	→ 7
6. Basal leaf blades usually linear, sometimes spatulate, blade much longer than wide	→ 8
7. Basal rosettes flattened to suberect; leaf blades trullate, spatulate, or narrowly rhombic to ovate, apex obtuse, red pigmentation often strong even in juvenile plants	C. rubra
7. Basal rosettes suberect to erect, seldom flattened; leaf blades broadly rhombic to deltate or reniform, apex obtuse to apiculate, red pigmentation often weak	C. perfoliata
8. Seeds often smooth or with low tubercles, not pebbly; leaf blades not glau- cous, green or pink	C. parviflora
8. Seeds often tuberculate and pebbly; leaf blades glaucous, gray, beige, or pink	→ 9
9. Flowers 3-5 mm diam	C. exigua
9. Flowers 6-12 mm diam	C. gypsophiloides
10. Plants with tubers sometimes connected by rhizomes	→ 11
10. Plants with rhizomes or woody caudices	→ 19
11. Bracts 2 or more, distal bracts leaflike or reduced to membranous scales; cauline leaves often strongly tapered in basal 1/2	→ 12
11. Bracts 1 or absent, (rarely 2 in C. caroliniana); cauline leaves seldom tapered in no more than basal 1/4	→ 15
12. Bracts all leaflike; tubers napiform	C. ogilviensis
12. Proximalmost bract leaflike, distal bracts reduced to membranous scales; tubers globose	→ 13
13. Petals white with yellow blotch at base	C. tuberosa
13. Petals white, pink, rose, magenta, cream, yellow, or yellow-orange, lacking yellow blotch at base	→ 14
14. Petals pink, rose, or magenta	C. rosea
14. Petals white, cream, yellow, or yellow-orange	C. multiscapa
15. Bracts absent; petals pink to magenta	C. umbellata
15. Bracts present; petals white, white with yellow blotch at base, yellow, orange, or candy-striped (sometimes pink, rose, or magenta in C. caroliniana, C. lanceolata, and C. virginica)	→ 16
16. Cauline leaf blades linear, 0.2-1.2 cm wide, tapered to slender base	→ 17
16. Cauline leaf blades lanceolate or spatulate to ovate, 0.4-2.5 cm wide, abruptly petiolate or sessile	→ 18
17. Petals white, pinkish, or rose, candy-striped, rarely yellow or orange, or white with pink-lavender candy-stripes; e North America to Texas	C. virginica
17. Petals white with yellow blotch at base; Alaska, Yukon	C. tuberosa
18. Basal leaves 6-21; cauline leaves petiolate; e North America	C. caroliniana
18. Basal leaves 1-6 or absent; cauline leaves sessile; w North American cordillera	C. lanceolata
19. Plants with woody caudices	→ 20
19. Plants rhizomatous	→ 22
20. Basal leaves and bracts with apex acute; petals white or pink to bright rose with yellow blotches at base, or white	C. acutifolia
20. Basal leaves and bracts (where present) with apex obtuse; petals usually pink to magenta, sometimes yellow or white	→ 21
21. Stems 1-10 cm; bracts absent; Alaska	C. arctica
21. Stems 10-50 cm; bracts present; not in Alaska	C. megarhiza
22. Bracts present; seeds (1-)3	→ 23
22. Bracts absent; seeds (1-)6	→ 24
23. Cauline leaves equal, sessile, blade lanceolate to ovate; basal leaf blades 1-5 cm wide	C. sibirica
23. Cauline leaves unequal, petiolate, blade linear to spatulate; basal leaf blades 0.1-1 cm wide	C. palustris
24. Rhizomes 0.5-3 mm diam.; Alaska, Yukon, n British Columbia	→ 25
24. Rhizomes 4-8 mm diam.; w United States	→ 26
25. Basal leaf baldes linear to narrowly spatualte, 1-10 × 0.1-1 cm	C. scammaniana
25. Basal leaf blades elliptic to spatulate, 1-8 × 1-2 cm	C. sarmentosa
26. Basal leaf blades deltate to ovate or cordate; cauline leaf blades 1-5 cm; petals white	C. cordifolia
26. Basal leaf blades spatulate to rhombic or ovate; cauline leaf blades 0.5-2 cm; petals pink to magenta	C. nevadensis