Sabatia

Herbs annual, biennial, or perennial, perennials sometimes stoloniferous, individual crowns then sometimes biennial; chlorophyllous, glabrous. Leaves cauline, opposite, often also basal. Inflorescences cymes, thyrses, heads, or paired or solitary flowers, cymes dichasial in species with opposite branching, monochasial in species with alternate branching. Flowers (4–)5–12(–14)-merous; calyx tube urceolate, campanulate, or obconic, lobes longer or shorter than tube; corolla pink, purplish pink, cream, or white, often with an adaxial yellow, yellowish green, or white eye encompassing the corolla tube and extending into the proximal parts of the lobes, rotate, glabrous, lobes much longer than tube, entire, plicae between lobes absent; stamens inserted in or immediately below (species 1–14, 17–20) or slightly but distinctly below (species 15 and 16) the corolla sinuses; anthers straight, recurved or recoiling circinately or curving or twisting helically, distinct; ovary sessile; style deciduous, initially deflexed to one side or less often erect, distinct, 2-cleft; stigmas 2, styles and stigmas often coiling helically; nectaries 5 at base of ovary, not clearly differentiated. Capsules cylindric to ovoid or globose. x = 7; aneuploidy common.

Distribution

North America, n Mexico, West Indies, temperate to subtropical areas.

Discussion

Species 21 (20 in the flora).

The orthographic variant Sabbatia has been widely used for those names cited here that were published during the nineteenth century and still later by G. C. Druce and J. K. Small. The spelling Sabatia was an intentional Latinization by M. Adanson and must be retained.

Sabatia capitata and S. gentianoides have sometimes been segregated as the genus Lapithea or as Sabatia sect. Pseudochironia Grisebach, distinguished by sessile rather than pedicellate flow­ers and merely curved rather than coiling anthers. These species further differ from the other species of Sabatia in having the filaments inserted slightly but distinctly below, rather than in, the sinuses of the corolla. Molecular phylogenetic studies by K. G. Mathews et al. (2015) con­firm the close relationship of these species to each other but support their retention in Sabatia.

Most species of Sabatia are protandrous and outbreeding. In most of the outbreeding species the styles are deeply cleft and the stigmas are linear, appearing as continuations of the style branches. Initially, these combinations of style branches and stigmas are helically coiled around each other and are deflexed to one side, while the stamen filaments are erect and the anthers are straight. Later, the style becomes erect and its branches uncoil and diverge, exposing the stigmatic surfaces, and the stamens diverge radially. The anthers coil or at least recurve circinately upon or following dehiscence. In S. capitata and S. gentianoides the style branch-stigma combinations are widely oblanceolate and are scarcely coiled at any stage, and the anthers remain straight or are slightly coiled helically after dehiscence. Sabatia arenicola and S. calycina have relatively small, homogamous flowers and are generally autogamous. In these species the style is not deflexed at anthesis. It and the stigmas, which are already receptive when the pollen is shed, are scarcely or not coiled until after pollination occurs. The anthers remain straight or nearly so after dehiscence (J. D. Perry 1971).

Great variation in plant and flower size occurs within Sabatia species, especially in the annuals and biennials. This variation is due to environmental factors, including shade, soil moisture, and the interaction of photoperiod with receding water levels or other conditions permitting seed germination (J. D. Perry 1971).

Stems of Sabatia species may be terete or four-angled. If the stems are angled, narrow wings may extend from the apex of the angles. Calyx tubes described here as campanulate or hemi­spheric are rounded at the base, whereas those described as obconic (or turbinate in some liter­ature, for example, R. L. Wilbur 1955) taper at the base. Some species are intermediate in this respect. Pedicel length in this treatment refers to the true pedicels beyond the most distal pair of bractlets, which may be minute, and the calyx, rather than to the ultimate divisions of the inflorescence.

Selected References

None.

Lower Taxa

Sabatia angularis, Sabatia arenicola, Sabatia arkansana, Sabatia brachiata, Sabatia brevifolia, Sabatia calycina, Sabatia campanulata, Sabatia campestris, Sabatia capitata, Sabatia decandra, Sabatia difformis, Sabatia dodecandra, Sabatia foliosa, Sabatia formosa, Sabatia gentianoides, Sabatia grandiflora, Sabatia kennedyana, Sabatia macrophylla, Sabatia quadrangula, Sabatia stellaris

Key

1	Flowers 7–12(–14)-merous.	> 2
2	Flowers sessile above bractlets, usually in heads.	> 3
3	Basal leaf blades oblong-spatulate, sharply differentiated from linear cauline leaves; cauline leaf blades 1–3 mm wide.	Sabatia gentianoides
3	Basal and cauline leaf blades similar, blades oblong to elliptic, 7–20(–25) mm wide.	Sabatia capitata
2	Flowers pedicellate.	> 4
4	Basal leaves usually present at flowering, blade oblanceolate to spatulate, sharply differentiated from linear to lanceolate cauline leaves.	Sabatia decandra
4	Basal leaves absent at flowering or similar to cauline leaves, blade linear to oblong-lanceolate.	> 5
5	Primary branching mostly opposite; calyx tube not or obscurely ridged, lobes linear-filiform.	Sabatia kennedyana
5	Primary branching alternate (rarely all opposite in S. foliosa); calyx tube dis­tinctly ridged, lobes linear to narrowly spatulate or foliaceous.	> 6
6	Stolons poorly developed or absent; internodes mostly 1.25+ times as long as subtending leaves; salt brackish (rarely fresh) marshes along the Atlantic Coast.	Sabatia dodecandra
6	Stolons well developed; internodes generally less than 1.25 times as long as subtending leaves; inland habitats, not brackish.	Sabatia foliosa
1	Flowers (4–)5(–7)-merous.	> 7
7	Calyx lobes with lateral veins (submarginal in lobes) more prominent than midvein, tubes with prominent, commissural ridges.	> 8
8	Leaf blades elliptic to ovate or obovate; corolla lobes 4–10(–13) mm; beaches, interdunal depressions, salt flats along the Gulf Coast.	Sabatia arenicola
8	Leaf blades linear to ovate; corolla lobes 8–25 mm; widely distributed, generally not in coastal saline habitats.	> 9
9	Basal leaves usually present at flowering; calyces usually shorter than or as long as corollas; corolla lobes elliptic-rhombic.	Sabatia formosa
9	Basal leaves absent at flowering; calyces usually as long as or longer than corollas; corolla lobes obovate or spatulate-obovate.	> 10
10	Leaf blades lanceolate-elliptic to ovate; corolla lobes obovate, less than 1.8 times as long as wide, apex abruptly ± acute; widely distributed.	Sabatia campestris
10	Leaf blades linear to narrowly lanceolate; corolla lobes narrowly spatulate-obovate, 1.8+ times as long as wide, apex rounded; c Arkansas.	Sabatia arkansana
7	Calyx lobes with midvein as or more prominent than lateral veins or, if linear-filiform, subulate, or setaceous, without discernible lateral veins, tubes not ridged below sinuses, or at most with low ridges from base to sinuses.	> 11
11	Flowers subsessile above bractlets or true pedicels to 10(–15) mm.	> 12
12	Stems terete; calyx lobes 0.1–3 mm; corolla lobes 4–7(–9) mm.	Sabatia macrophylla
12	Stems 4-angled at least distally; calyx lobes (2–)3–8(–14) mm; corolla lobes 4.5–21 mm.	> 13
13	Stems 4-angled throughout, the angles with wings 0.1–0.5 mm.	Sabatia quadrangula
13	Stems at least proximally terete or nearly so (distally ± 4-angled, wings absent).	> 14
14	Plants annual, biennial, or occasionally short-lived perennial; stems with all branching opposite or distal branching all or partly alternate; corollas pink or rarely white.	Sabatia brachiata
14	Plants perennial; stems with all branching opposite; corollas white.	Sabatia difformis
11	Pedicels above bractlets 10–100(–150) mm.	> 15
15	Stems 4-angled with wings distally 0.2–0.3 mm wide.	Sabatia angularis
15	Stems terete or nearly so, wings absent.	> 16
16	Calyx lobes oblanceolate to spatulate or foliaceous.	Sabatia calycina
16	Calyx lobes setaceous, filiform, or subulate to linear.	> 17
17	Calyces generally less than 1/2 as long as corollas, lobes 3–8 mm; corollas white.	Sabatia brevifolia
17	Calyces generally 1/2+ as long as corollas, lobes (4–)6–25(–30) mm; corollas pink or rarely white.	> 18
18	Mid-stem leaves generally less than 2.5 mm wide, distal leaf blades filiform; corolla lobes (13–)17–30 mm.	Sabatia grandiflora
18	Mid-stem leaf blades generally 2.5+ mm wide, distal leaf blades linear; corolla lobes 5–24 mm.	> 19
19	Plants perennial, stems clustered; calyces usually 0.8+ times as long as corollas.	Sabatia campanulata
19	Plants annual or biennial, single-stemmed; calyces usually less than 0.8 times as long as corollas.	Sabatia stellaris