Hosackia
Edwards’s Bot. Reg. 15: plate 1257. 1829.
Herbs, perennial, unarmed. Stems erect, ascending, decumbent, or procumbent, glabrous or glabrate to pubescent, puberulent, villous, or canescent to silky. Leaves alternate, odd-pinnate; stipules present, caducous, leafy or scarious; petiolate; leaflets 3–19, regularly arranged, blade margins entire, surfaces glabrous or pubescent. Inflorescences 1–20-flowered, axillary, umbels or solitary flowers; bract usually present (absent in H. alamosana), medial or subtending umbel. Flowers papilionaceous; calyx actinomorphic to slightly zygomorphic, cylindric to obconic-cylindric, lobes 5; corolla yellow, cream, white, pink, purple, red, or lurid, keel equaling or longer than symmetrically positioned wings; stamens 10, diadelphous; anthers basifixed, relatively small, dehiscing longitudinally; style glabrous, without collar; stigma terminal. Fruits legumes, exserted from calyx, straight, not deflexed, linear to oblong, subterete to quadrate, abruptly short-beaked, dehiscent, usually glabrous, sometimes ± hairy or glabrate. Seeds (2–)4–20(or 21), mottled, oblong, ovoid, obovoid, or reniform. x = 7.
Distribution
w North America, Mexico, Central America (Guatemala).
Discussion
Species 14 (9 in the flora).
Five species of Hosackia are found in Mexico and not in the flora area: H. confinis (Greene) Brand, H. guadalupensis (Greene) Brand, H. hintoniorum (B. L. Turner) D. D. Sokoloff, H. mexicana Bentham, and H. repens G. Don, which occurs also in Guatemala.
Throughout the twentieth century, Hosackia usually was included within Lotus (D. Isely 1981, 1993). Phylogenetic work, both morphologic (A. M. Arambarri 2000) and molecular (G. J. Allan and J. M. Porter 2000; Allan et al. 2003; D. D. Sokoloff et al. 2007), has shown that Hosackia is distinct from the Eurasian Lotus and the North American Acmispon. Morphologic features that distinguish Hosackia include the well-developed stipules versus glandlike or reduced in Acmispon, and 3–15-pinnate leaves (proximal leaflet pairs not in stipular position as in Lotus) with regularly arranged leaflets versus irregularly or ± palmately arranged in Acmispon. Hosackia is distinctive in Loteae also by frequently being found in more or less wet habitats.
For definitions of “implicate” and “implicate-ascending” (in reference to the banner petal), see the discussion under 123. Acmispon.
Selected References
None.
Lower Taxa
Key
| 1 | Herbs mat-forming, 5–40 cm, taprooted, sometimes with woody caudex; stems usually decumbent, sometimes ascending or procumbent; leaves: rachis 0.5–1.5 cm, leaflets 3–5(–7), blade surfaces glabrous; umbels 1–3(or 4)-flowered; petal claws ± equaling calyx tube; legumes ascending to erect. | > 2 |
| 2 | Flowers (7–)8–10 mm, banner yellow, wings and keel whitish yellow, calyx lobes triangular to triangular-subulate, 0.5–1 mm; legumes narrowly oblong, compressed, leathery; seeds (2–)4–7, oblong; stipules inconspicuous, scarious. | Hosackia yollabolliensis |
| 2 | Flowers 5–7(–9) mm, banner yellow, wings and keel white or cream, becoming reddish tinged, calyx lobes lanceolate, 0.5–2 mm; legumes linear-oblong, turgid, thinly leathery; seeds (8–)10–13(–15), reniform, flattened; stipules 1.5–3.5 mm, membranous. | Hosackia alamosana |
| 1 | Herbs not mat-forming, 10–150 cm, usually rhizomatous, stoloniferous, or root-spreading, sometimes with caudex; stems usually erect to ascending, sometimes decumbent; leaves: rachis 1–12 cm, leaflets (3 or)5–15(–19), blade surfaces glabrous or hairy; umbels (1–)3–20-flowered; petal claws usually longer, sometimes ± equaling to slightly longer, than calyx tube; legumes ± ascending to ± inclined. | > 3 |
| 3 | Corolla banner yellow; stems decumbent to ascending; peduncles equaling or longer than subtending leaf, bract absent or subtending umbel; seeds (6–)8–20(or 21). | > 4 |
| 4 | Leaflet blades appressed-hairy to hirsute or glabrous; calyx green, hairy; petal claws ± equaling to slightly longer than calyx tube, banner implicate-ascending; legumes leathery, not septate. | Hosackia oblongifolia |
| 4 | Leaflet blades glabrous; calyx reddish, glabrous; petal claws longer than calyx tube, banner reflexed to 180°; legumes thinly leathery, incompletely septate. | > 5 |
| 5 | Stems ± fleshy or not; corolla: wings white or cream, keel yellow, wings longer than keel; legumes linear-oblong; peduncle bract 1(or 3)-foliolate or absent; leaf rachis 2–7 cm, leaflet blades (7–)10–25 mm. | Hosackia pinnata |
| 5 | Stems fleshy, base often spongy; corolla: wings and keel pale to dark pink, sometimes whitish, keel pink- to purple-tipped, wings equaling or longer than keel; legumes oblong; peduncle bract 1 or 3(–7)-foliolate; leaf rachis 1–4 cm, leaflet blades 6–20 mm. | Hosackia gracilis |
| 3 | Corolla banner red, purple, pink, rose, or white, or greenish or whitish becoming marked with red or purple; stems usually erect or ascending, sometimes decumbent (H. rosea); peduncles usually shorter than subtending leaf (equaling or longer in H. rosea), bract absent or medial, sometimes subtending umbel (H. incana); seeds 3–12. | > 6 |
| 6 | Herbs densely silvery- to golden-villous or -canescent; corolla banner red, wings and keel white, keel apex obtuse; leaflets (5–)7–11(–15). | Hosackia incana |
| 6 | Herbs villous and legume ± hairy, or sparsely strigulose, puberulent, or glabrate, sometimes glabrous (H. stipularis); corolla purple, pink, or white, wings sometimes white, or greenish or whitish becoming marked with red or purple, keel apex acute; leaflets (7–)9–15(–19). | > 7 |
| 7 | Stipules widely ovate to lanceolate, base auriculate or subauriculate; leaf rachis 2–8 cm; calyx ± hairy, sometimes glandular; corolla banner and keel purple or pink, wings white; legumes thinly leathery. | Hosackia stipularis |
| 7 | Stipules triangular or ovate to lanceolate, base not auriculate or subauriculate; leaf rachis 6–12 cm; calyx glabrous; corolla banner, keel, and wings white to pinkish or rose, or initially greenish or whitish with red or lurid patches, strips, or tips; legumes leathery. | > 8 |
| 8 | Umbels 6–10(–12)-flowered; corollas symmetric, white to pinkish or rose, becoming red- or pink-striate or tipped, wings longer than keel; legumes oblong, (15–)30–40 mm, not septate; peduncles little elongating in fruit; stems ± fleshy or not. | Hosackia rosea |
| 8 | Umbels 8–20-flowered; corollas asymmetric, greenish or whitish becoming marked with red or purple, wings ± equaling keel; legumes linear, (10–)35–70 mm, incompletely septate; peduncles elongating in fruit; stems fleshy. | Hosackia crassifolia |