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milkpea

Small's milkpea

Habit Herbs, perennial, [subshrubs, rarely shrubs], unarmed; with rhizomes, from woody taproot elongate or fusiform. Herbs from a thick-fusiform, woody taproot.
Stems

procumbent or twining and climbing, glabrous or with spreading or appressed hairs.

procumbent, distally twining, densely to sparsely hirsute-villous to hirsute, hairs loosely retrorsely spreading or antrorsely spreading-ascending.

Leaves

alternate, unifoliolate or odd-pinnate;

stipules present, deciduous or persistent;

petiolate;

leaflets 1 or 3(–9), stipels persistent, blades 6–85 mm, margins entire, surfaces pubescent or glabrous.

Leaflets

3, blades broadly elliptic to broadly elliptic-oblong or suborbiculate, 8–25 × 6–20 mm, herbaceous, veins not raised, apex rounded or usually shallowly retuse, surfaces villous-hirsute, with ascending hairs or adaxially minutely hirsute.

Inflorescences

1–25(–38)-flowered, axillary [terminal], usually pseudoracemes, pedunculate or without axis and flowers in axillary fascicles, sometimes flowers solitary;

rachis with slightly swollen nodes;

bracts present, setaceous;

bracteoles minute, caducous, rarely tardily so.

flowers solitary and axillary or 2–6 in reduced pseudoracemes on distal 1/8–1/4 of axis;

axis (5–)20–60(–90) mm.

Flowers

papilionaceous, solitary, paired, or fascicles of 2 or 3 at nodes;

calyx campanulate, lobes 5 appearing as 4, adaxial 2 completely connate;

corolla usually purplish to bluish, pink, rose, violet, or lavender, rarely white [red], 6–15(–17) mm;

petals subequal, banner orbiculate to ovate or obovate-orbiculate, margins slightly inflexed or appendaged, apex rounded, wings narrow or obovate, adherent to keel, keel obtuse and almost straight, subequal to or longer than wings, carinate or moderately incurved;

stamens 10, diadelphous [pseudomonadelphous], vexillary stamen free or proximally connate from middle;

anthers dorsifixed;

ovary subsessile;

style filiform, glabrous;

stigma terminal, capitate;

nectary at ovary base.

calyx 6–7 mm, strigose to hirsute, lobes greenish yellow to tan on inner surface when dry;

corolla not persisting after anthesis, lavender-pink to purple, lighter when dry, 10–15 mm.

Fruits

legumes, sessile, brown, laterally compressed, straight or weakly to strongly falcate, linear, with false septae between seeds, elastically dehiscent, pubescent.

Legumes

straight, 25–50 × 5 mm, densely strigose, sometimes white-glaucous.

Seeds

1–12, brown or brownish orange, flattened, oblong, 3–7 mm, estrophiolate.

7–11.

x

= 10.

Galactia

Galactia smallii

Phenology Flowering Mar–Oct (or year-round).
Habitat Pine rockland-slash pine with a shrub canopy of saw palmetto (Serenoa repens), wax myrtle (Myrica cerifera), poisonwood (Metopium toxiferum), and willow Bustic (Sideroxylon salicifolium) over outcropping oolitic limestone.
Elevation 0–10 m. (0–0 ft.)
Distribution
from USDA
United States; Mexico; Central America; South America; West Indies; Asia; Africa; Australia
[BONAP county map]
from FNA
FL
[BONAP county map]
Discussion

Species ca. 110 (21 in the flora).

Most Galactia species are native to the Americas, distributed fairly evenly across the southeastern and south-central United States, Mexico, West Indies, Central America, and South America. Diversity in the flora area is concentrated in Florida and Texas, with relatively fewer species in Mexico and Central America. Three species of Galactia are native to Asia, Africa, and Australia. An overview of the genus in the flora area and a summary of previous studies worldwide were provided in G. L. Nesom (2015). The Texas species G. watsoniana W. C. Holmes & Singhurst is a synonym of Cologania pallida Rose (Nesom).

Three sections have been recognized within Galactia (A. Burkart 1971), emphasizing the South American species. Most species of Galactia, including all of those in the flora area, are placed in sect. Odonia (Bertoloni) Burkart in the sense of Burkart.

Galactia forms a group in the Diocleinae Bentham together with three or four other genera: Camptosema Hooker & Arnott, Collaea de Candolle, and Lackeya. R. H. Maxwell and D. W. Taylor (2003) included the Caribbean Rhodopis Urban in their Galactia clade. Phylogenetic studies indicate that Galactia is not monophyletic (L. P. de Queiroz et al. 2003; S. M. Sede et al. 2008, 2009; G. B. Ceolin 2011), but relatively few species have been included in analyses. Galactia appears to be paraphyletic without the inclusion of some species of Camptosema and perhaps the entire genus Collaea. In addition, the sections as circumscribed by Burkart do not appear to be monophyletic.

R. H. Maxwell (1979) placed the eastern North American Dioclea multiflora in Galactia as G. mohlenbrockii R. H. Maxwell; R. H. Fortunato et al. (1996) segregated D. multiflora as the monospecific Lackeya. This placement is supported by molecular analyses (L. P. de Queiroz et al. 2015).

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

Galactia smallii is endemic to rocky habitats in Miami-Dade County and is recognized by its prostrate habit with stems distally twining, stems and leaves variably spreading-hairy to strigose (antrorse or retrorse), and relatively large flowers, which often appear abundantly after fires. The lectotype (Small 8633, NY) has spreading cauline vestiture (though strongly glabrescent and not evident on portions of the stems). Other collections from the Miami-Dade County rocklands essentially identical otherwise in morphology have either spreading hairs or retrorse or antrorse hairs, and it appears that all of these plants should be considered as a single population system with variable vestiture. Other species apparently with variable orientation of vestiture are G. brachypoda, G. joselyniae, G. microphylla, and G. pinetorum.

Galactia smallii is in the Center for Plant Conservation’s National Collection of Endangered Plants.

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

Key
1. Leaflets 1.
G. marginalis
1. Leaflets 3 or 5–9.
→ 2
2. Leaflets 5–9.
→ 3
3. Leaflets (5 or)7(or 9); corollas white; flowers 3–11, distal on axis; Florida, Georgia, South Carolina.
G. elliottii
3. Leaflets 5; corollas pink to purple, purple-red, violet-red, or lavender; flowers axil­lary, solitary or 2–5 in pseudoracemes; Texas.
G. heterophylla
2. Leaflets usually 3, rarely 5.
→ 4
4. Stems mostly erect, not twining, usually alternately bent at nodes; inflorescences subsessile, flowers 1–6.
G. erecta
4. Stems procumbent or climbing-twining, not bent at nodes; inflorescences pedun­culate, flowers 2–25(–38), or sessile or subsessile and 1-flowered.
→ 5
5. Stems climbing-twining.
→ 6
6. Corollas 11–14(–15) mm; stems loosely strigose with short, loosely appressed, retrorse hairs, strongly lignescent.
G. fasciculata
6. Corollas 7–11(–14) mm; stems strigose to hirsute or hirsute-pilose, herbaceous to ± lignescent (G. striata).
→ 7
7. Banners striped with white lines; localities coastal and near-coast.
G. striata
7. Banners not striped; localities inland to coastal.
→ 8
8. Legumes falcate; flowers 1–5, solitary and subsessile or 2–5 on inflorescence axis 1–4(–40) mm.
G. texana
8. Legumes straight; flowers 1–8(–16), solitary and pedicellate or 2–8(–16) on inflorescence axis 10–150(–280) mm.
→ 9
9. Stems strigose with antrorse hairs; leaflet blades linear-oblong to narrowly oblong or narrowly elliptic, 2–4(–6) mm wide; Florida.
G. grisebachii
9. Stems strigose or hirsute to hirsute-villous with spreading-deflexed or retrorse hairs; leaflet blades oblong to elliptic, elliptic-lanceolate, or oblong-lanceolate, 5–21(–25) mm wide; Texas, or broadly distributed in c, e United States.
→ 10
10. Leaflet blades narrowly oblong to oblong-lanceolate, 6–14 mm wide; legumes 35–65 mm; seeds 12–15; Florida, Texas.
G. longifolia
10. Leaflet blades elliptic to broadly elliptic or oblong to lanceolate-elliptic, 5–21(–25) mm wide; legumes 20–50(–52) mm; seeds 5–11; c, e United States including Texas.
→ 11
11. Leaflet blades mostly elliptic to broadly elliptic, (5–)10–21(–25) mm wide; stems moderately to densely hirsute to hirsute-villous with spreading-deflexed hairs; corollas 7–10 mm.
G. regularis
11. Leaflet blades oblong to lanceolate-elliptic, 5–15(–17) mm wide; stems sparsely to moderately stri­gose with tightly to loosely appressed, retrorse hairs, sometime glabrate; corollas 9–14 mm.
G. volubilis
5. Stems procumbent at least proximally, not distinctly climbing-twining, some­times weakly twining distally.
→ 12
12. Herbs usually producing filiform rhizomes at nodes, these producing subterranean flowers and 1-seeded fruits.
G. canescens
12. Herbs without rhizomes at nodes, without subterranean flowers and fruits.
→ 13
13. Calyx lobes brown to reddish brown on inner surface when dry; corollas distinctly dark reddish when dry, persisting after anthesis, sometimes still present in mature fruit.
G. mollis
13. Calyx lobes greenish yellow to tan on inner surface when dry; corollas light whitish to blue, pinkish, or purplish when dry, not persisting after anthesis.
→ 14
14. Leaflets ± leathery to leathery, veins raised on both surfaces.
→ 15
15. Leaflet blades mostly linear-oblong or narrowly oblong, 2–8(–11) mm wide; Florida.
G. pinetorum
15. Leaflet blades elliptic, oblanceolate-elliptic, oblong-elliptic, elliptic-lanceolate, or broadly lanceolate, (4–)7–25(–32) mm wide; Florida and Alabama north to New Jersey.
→ 16
16. Stems: several to most internodes (especially those toward base) longer than largest leaflet of adjacent nodes, hairs on stem 0.1–0.8 mm; leaflet blades (4–)10–25(–32) mm wide; flowers usually (3–)5–15(–25), rarely 1 or 2.
G. brachypoda
16. Stems: internodes usually shorter, sometimes longer, than largest leaflet of adjacent nodes, hairs on stems 0.1–0.3 mm; leaflet blades (4–)7–10(–18) mm wide; flowers solitary or 2–4.
G. minor
14. Leaflets herbaceous, veins not raised (except strong raised abaxially in G. joselyniae).
→ 17
17. Stems strigose; Arizona, New Mexico, Texas.
→ 18
18. Leaflet blades oblong-elliptic to elliptic-ovate; flowers (2–)5–18(–30), corollas 11–12 mm.
G. wrightii
18. Leaflet blades mostly broadly oblong-elliptic to suborbiculate; flowers solitary or 2–8, corollas 6–8 mm.
G. joselyniae
17. Stems tomentose to hirsute-villous or hirsute; se United States.
→ 19
19. Leaflet blades (14–)20–55 × (10–)15–35 mm; flowers 5–12(–25).
G. floridana
19. Leaflet blades 8–30 × 5–20 mm; flowers solitary and axillary or 2–6.
→ 20
20. Inflorescence axis 10–20 mm; calyces 3–4 mm; corollas 6–7 mm; Florida panhandle, s Alabama.
G. microphylla
20. Inflorescence axis (5–)20–60(–90) mm; calyces 6–7 mm; corollas 10–15 mm; s Florida.
G. smallii
Source FNA vol. 11. Author: Guy L. Nesom. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae Fabaceae > subfam. Faboideae > Galactia
Sibling taxa
G. brachypoda, G. canescens, G. elliottii, G. erecta, G. fasciculata, G. floridana, G. grisebachii, G. heterophylla, G. joselyniae, G. longifolia, G. marginalis, G. microphylla, G. minor, G. mollis, G. pinetorum, G. regularis, G. striata, G. texana, G. volubilis, G. wrightii
Subordinate taxa
G. brachypoda, G. canescens, G. elliottii, G. erecta, G. fasciculata, G. floridana, G. grisebachii, G. heterophylla, G. joselyniae, G. longifolia, G. marginalis, G. microphylla, G. minor, G. mollis, G. pinetorum, G. regularis, G. smallii, G. striata, G. texana, G. volubilis, G. wrightii
Synonyms Heterocarpaea, Odonia G. prostrata
Name authority P. Browne: Civ. Nat. Hist. Jamaica, 298, plate 32, fig. 2. (1756) H. J. Rogers ex A. Herndon: Rhodora 83: 471. (1981)
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