Croton sect. Lasiogyne

Rossine, Yuri, Melo, André Laurênio De, Athiê-Souza, Sarah Maria & Sales, Margareth Ferreira De, 2023, Understanding the “ Marmeleiros ”: a taxonomic treatment of Croton sect. Lasiogyne (Euphorbiaceae) in Brazil, Phytotaxa 584 (4), pp. 219-250 : 227

Identification key for the species of Croton sect. Lasiogyne occurring in Brazil

1. Leaf blade strongly bifacial, abaxial surface shiny, light green, yellowish or silvery to ferruginous................................................2

- Leaf blade slightly bifacial, abaxial surface opaque, light green, grayish or yellowish.....................................................................8

2. Abaxial surface of the leaf blade light green or yellowish to silver, never ferruginous; sepals of the pistillate flower reduplicated vertically and horizontally..................................................................................................................................................................3

- Abaxial surface of the leaf blade silver to ferruginous; sepals of the pistillate flower reduplicated only vertically .........................4

3. Branches monopodial; stipules helicoidal; leaf blade ovate, trichomes on adaxial surface dentate-lepidote to lepidote, abaxial surface never yellowish, venation actinodromous perfectly reticulate; capsule obloid ...................................................... C. micans

- Branches sympodial; stipules linear to lanceolate; leaf blade lanceolate to elliptic, stellate, stellate-porrect, sometimes dentatelepidote to lepidote trichomes on adaxial surface, abaxial surface silver to yellowish, venation eucamptodromous; capsule ovoid to obloid.................................................................................................................................................................... C. argyrophyllus

4. Branches brown to reddish; nectary disk of the staminate flower with simple trichomes; petals on pistillate flowers developed (up to 5 mm long................................................................................................................................................................. C. sacaquinha

- Branches yellowish, brown, gray or silvery to ferruginous; nectary disk of the staminate flower glabrous, or with stellate-lepidote trichomes; petals absent, reduced (up to 1 mm long), or transformed into glands in the pistillate flower ........................................5

5. Styles 2-fid or 2-partite.......................................................................................................................................................................6

- Styles multifid or multipartite ............................................................................................................................................................7

6. Dioecious shrub; branches sympodial; adaxial surface of the leaf blade glabrous or with stellate to stellate-lepidote trichomes, venation eucamptodromous; thyrse axillary; 10–15 stamens; sepals of the pistillate flower equal in size, style 2-fid; capsule silver to ferruginous; seed surface smooth............................................................................................................................... C. suassunae

- Monoecious shrub; branches monopodial; adaxial surface of the leaf blade with simple, 2–5-radiate or dentate-lepidote trichomes, venation brochidodromous; thyrse terminal or axillary; 5–6 stamens; sepals of the pistillate flower slightly unequal in size, style 2-partite; capsule yellow to orangish, seed surface rugose ...................................................................................... C. claussenianus

7. Shrub (2–10 m tall); stipules linear; venation brochidodromous; pistillate flower with triangular sepals, nectary disk with 5 free segments, glabrous; capsule spheroid, unlobed; seeds smooth .............................................................................................. C. limae

- Shrub (up to 3 m tall); stipules lanceolate to auriculate; venation eucamptodromous; pistillate flower with ovate to oblong sepals, nectary disk 5-lobed, with stellate trichomes; capsule ovoid to subspheroid, 3-lobed, seeds papillose-rugose ................. C. tricolor

8. Tree (3–20 m tall); young branches and petioles with dendritic trichomes; thyrse terminal or axillary; petals reduced (ca. 1 mm long) in pistillate flowers, filiform, styles always patent, 24–36 (–40) stigmatic tips; capsule muricate .................... C. floribundus

- Shrubs (up to 8 m tall); young branches and petioles with stellate to stellate-lepidote trichomes; thyrse only terminal; petals absent on pistillate flower, styles patent or ascending, 12–24 stigmatic tips; capsule non-muricate............................................................9

9. Branches, abaxial surface of the leaf blade, thyrse, ovary, and capsules with stellate-lepidote to lepidote trichomes; style multifid, united for ¾ of its length, forming a column; seed smooth...................................................................................... C. blanchetianus

- Branches, abaxial surface of the leaf blade, thyrse, ovary, and capsules with stellate trichomes; style multipartite, free; seed rugose or papillose-rugose ...........................................................................................................................................................................10

10. Stipules linear; leaf blade lanceolate; cymules congested; bracts lanceolate to oblong; sepals of the pistillate flower reduplicated horizontally or vertically and horizontally, glabrous internally, styles ascending........................................................ C. compressus

- Stipules reniform, flabelliform to auriculate, or less common lanceolate; leaf blade cordiform; cymules lax; bracts lanceolate or 3-lobed; sepals of the pistillate flower reduplicated vertically and horizontally, densely covered by stellate trichomes internally, styles patent ................................................................................................................................................................. C. jacobinensis