Vicia ludoviciana
Fl. N. Amer. 1: 271. 1838.
Herbs annual or winter annual. Stems sprawling or climbing, slender to robust, 2–20 dm. Leaves 2–10 cm; tendrils branched; stipules much smaller than leaflets, semisagittate, without nectariferous patch; leaflets 7–14, blades ovate to linear, 5–25 × 1–11 mm, apex acute to emarginate, surfaces glabrous or puberulent. Inflorescences 2–19-flowered, 1–15 cm, or flowers 1, ± shorter than subtending leaf rachis. Flowers 4–7 mm; calyx base symmetric, lobes subequal, shorter than or equal to tube; corolla deep blue to bluish purple or pinkish white to light lavender, banner pandurate, blade equal to or longer than claw, glabrous; style compressed adaxially, pubescent apically. Legumes yellow to brown, flat, rhombic-oblong, 16–30 × 4–6 mm, oblique-tipped, glabrous; stipe to 1 mm. Seeds 4–8, brownish gray, mottled dark purple, subglobose to compressed-subglobose, 2.2–2.5 mm diam.; hilum encircling 1/4–1/3 circumference of seed.
Distribution
North America, n Mexico.
Discussion
Varieties 2 (2 in the flora).
J. S. Lassetter (1984) showed that the taxa traditionally treated as Vicia exigua, V. leavenworthii, V. ludoviciana, and V. producta are morphologically confluent and part of one evolving species complex. Within the complex, there is a strong tendency toward cleistogamy in populations traditionally delimited as V. leavenworthii: styles and anthers are shorter and pollination takes place before flowers open and peduncles fully elongate. Lassetter treated cleistogamous populations as var. leavenworthii and all other populations as var. ludoviciana.
J. S. Lassetter (1984), D. Isely (1998), and S. L. Broich (2007) presented more detailed treatments of vars. leavenworthii and ludoviciana, delimiting two races within var. leavenworthii and five races within var. ludoviciana.
Selected References
None.
Key
| 1 | Leaflets 7–10(–14); flowers opening after peduncle and internode elongation, without young fruit when first open. | Vicia ludoviciana var. ludoviciana |
| 1 | Leaflets 11–14; flowers opening before peduncle and internode elongation, usually with young fruit when first open. | Vicia ludoviciana var. leavenworthii |