Key to species of Adesmia ser. Psoraleoides

1. Slightly lignified plants, subshrubs and shrubs ............................................................................................................ 2

- Herbaceous plants......................................................................................................................................................... 7

2. Pedicels erect, even in fruit. Leaflets 1.6–5.0 × 0.6–2.2 mm, generally conduplicate .................................... A. tristis

- Pedicels reflexed after anthesis. Leaflets 6.0–20.0 × 2.1–10.0 mm, generally flat ...................................................... 3

3. Branches and leaves glabrous, only the inflorescences pubescent ............................................................................... 4

- Branches, leaves and inflorescences pubescent ........................................................................................................... 5

4. Plants up to 35 cm tall; leaflets 10–13 × 5–8 mm, pinnately veined....................................................... A. sessilifolia

- Plants 70–90 cm tall; leaflets 5.5–15.0 × 2.0– 4.8 mm, single-veined..................................................... A. paranensis

5. Inflorescences lax; flowers 7–9(–10) mm in length ............................................................................... A. rocinhensis

- Inflorescences dense; flowers 14.0– 19.5 mm in length................................................................................................ 6

6. Plants with prominent leaf scars and persistent stipules; racemes short, corymbose, aril absent ............... A. reitziana

- Plants without leaf scars; racemes long, seeds arillate ......................................................................... A. psoraleoides

7. Racemes with axillary flowers at the base..................................................................................................... A. araujoi

- Racemes or panicles without axillary flowers .............................................................................................................. 8

8. Leaflets broadly elliptic, suborbicular or obovate, 3.0–7.0 mm wide .......................................................................... 9

- Leaflets elliptic, oblong, obovate or rarely ovate, 0.7–2.8(–4.0) mm wide................................................................ 10

9. Leaves with 2–4(–5) pairs of leaflets. Pedicels 6.5–7.5 mm long. Hemicraspedium with 2–4(–5) orbicular articles... .......................................................................................................................................................................... A. valsii

- Leaves with (3–)5–8(–9) pairs of leaflets. Pedicels 1.5–5.0 mm long. Hemicraspedium with (2–)4–7 subquadrangular articles......................................................................................................................................................... A. sulina

10. Hemicraspedium articles 2.5–3.5 × 1.6–3.3 mm. Seeds with very short aril ................................................. A. ciliata

- Hemicraspedium articles 3.5–4.8 × 2.7–3.5 mm. Seeds with well-developed aril........................................ A. arillata