Cnidoscolus, Pohl, 1827

Oliveira, Cellini Castro De, Melo, André Laurênio De & Silva, Marcos José Da, 2021, Synopsis of Cnidoscolus (Euphorbiaceae) in midwestern Brazil, including taxonomic updates, a new species, and a reestablishment of C. neglectus, Phytotaxa 500 (3), pp. 179-200 : 181-182

Key to species of Cnidoscolus occuring in the Midwest region of Brazil

1. Leaves with acropetiolar glands .........................................................................................................................................................2

- Leaves with basilaminar glands..........................................................................................................................................................4

2. Trees 4–20 m tall; stamens 7–8 ......................................................................................................................... 7. C. paucistamineus

- Subshubs or shrubs 0.25–4 m tall; stamens 10–17.............................................................................................................................3

3. Subshrubs 30–60 cm tall; leaf blade with lanceolate lobes, base acute or rounded and margin entire; stamens basally glabrous; staminate disc lobed; ovary pyriform; pistillate disc denticulate; fruits globose with the apex slightly obtuse .................................. .................................................................................................................................................................................... 8. C. tridentifer

- Shrubs 1.5–4 m tall; leaf blade with ovate lobes, ovate-triangular, ovate-elliptical or ovate-oblong, base cordate, and margin irregularly dentate; stamens basally villous; staminate disc unlobed; ovary oblongoid or ovoid; pistillate disc not denticulate; fruits oblong-ellipsoid with the apex shortly acuminate......................................................................................................... 9. C. vitifolius

4. Leaves always unlobed, the leaf blade oblong, lanceolate or lyrate-pinnatisect; fruits circular ........................................................5

- Leaves 3–5-palmatilobed and rarely unlobed on the same plant near the inflorescence; fruits globose, oblongoid, oblongellipsoid ..............................................................................................................................................................................................6

5. Leaves petiolate, densely arranged at plant base in the form of a rosette or at the ends of the stem or branches; staminate disc villous; ovary pubescent; pistillate disc denticulate; seeds oblongoid ................................................................1. C. albomaculatus

5. Leaves sessile, distributed along the branches; staminate disc glabrous; ovary glabrous; pistillate disc not denticulate; seeds ellipsoid .................................................................................................................................................................5. C. maracayensis

6. Plants usually decumbent; pistillate flowers with connate tepals .................................................................................... 2. C. aurelii

- Plants always erect; pistillate flowers with free tepals.......................................................................................................................7

7. Leaves with the base truncate and margin irregularly dentate; stamens 10, villous basally; ovary glabrescent.................................. .................................................................................................................................................................................... 4. C. mcvaughii

- Leaves with the base hastate or cordate and margin entire and serrate; stamens 15–20, glabrous basally; ovary pubescent.............. ............................................................................................................................................................................................................8

8. Leaf margin serrate; stipules conspicuously papillose; dichasia velutinous with 15–20 flowers; seeds elliptic-obovoid................... ............................................................................................................................................................................................ 3. C. cervii

- Leaf margin entire; stipules slightly papilliform; dichasia pubescent with more than 30 flowers; seeds oblongoid........................... ..................................................................................................................................................................................... 6. C. neglectus