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Wright's milkpea

milkpea

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

procumbent proximally, weakly twining distally, strongly lignescent, densely to sparsely strigose, hairs retrorsely appressed to slightly spreading.

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

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 oblong-elliptic to elliptic-ovate, 15–48 × 5–18 mm, herbaceous, veins not raised, apex rounded to obtuse or shallowly retuse, surfaces moderately to densely strigose-sericeous and glaucous abaxially, sparsely to densely short-strigose-sericeous with closely appressed hairs to pubescent with soft, spreading-erect hairs, sometimes strigose to glabrous, adaxially.

Inflorescences

flowers (2–)5–18(–30) in pseudoracemes, usually in fascicles, axis rarely 10 mm and 2- or 3-flowered;

axis (10–)35–200(–250) mm.

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

calyx 5–7 mm, loosely short-strigose to hirsute-pubescent, lobes greenish yellow to tan on inner surface when dry;

corolla not persisting after anthesis, pink to purple-rose to lavender, lighter when dry, 11–12 mm.

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.

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 × 4–5 mm, moderately to densely strigose to strigose-sericeous.

Seeds

(3–)5–9.

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

x

= 10.

Galactia wrightii

Galactia

Phenology Flowering May–Aug.
Habitat Grasslands, desert scrub, oak-juniper and oak woodlands, granite crevices, igneous talus, among boulders, gravelly alluvium.
Elevation 700–1900 m. (2300–6200 ft.)
Distribution
from FNA
AZ; NM; TX; Mexico (Chihuahua, Sonora)
[WildflowerSearch map]
[BONAP county map]
from USDA
United States; Mexico; Central America; South America; West Indies; Asia; Africa; Australia
[BONAP county map]
Discussion

Galactia wrightii is characterized by twining stems, mostly oblong-elliptic leaflets with glaucous abaxial surfaces, relatively long inflorescences with numerous flowers and relatively large corollas, and strigose-sericeous fruits. The type of var. mollissima is a plant with vestiture more spreading than normal; such variants are scattered through the range in Arizona, as cited by Kearney and Peebles, as well as in Texas.

Plants in southwestern New Mexico and southeastern Arizona (especially the Huachuca Mountains but not the Chiricahua Mountains) tend to have reduced vestiture; the leaves are sometimes completely glabrous. Such plants extend southward in Mexico along the Chihuahua-Sonora border region. Intermediates are numerous, especially in Arizona, and no distinct boundary seems evident. In Texas, G. wrightii is known from four counties of the trans-Pecos and Big Bend regions.

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

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.)

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. FNA vol. 11. Author: Guy L. Nesom.
Parent taxa Fabaceae > subfam. Faboideae > Galactia Fabaceae > subfam. Faboideae
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. smallii, G. striata, G. texana, G. volubilis
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 G. tephrodes, G. wrightii var. mollissima Heterocarpaea, Odonia
Name authority A. Gray: Smithsonian Contr. Knowl. 3(5): 44. (1852) P. Browne: Civ. Nat. Hist. Jamaica, 298, plate 32, fig. 2. (1756)
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