Vitex, Linnaeus, 1753

Meerts, Pierre, 2018, Synopsis of the genus Vitex (Lamiaceae) in the Democratic Republic of the Congo, Plant Ecology and Evolution 151 (3), pp. 380-392 : 382-383

Key to the species of Vitex in D.R. Congo

1. Leaflets coarsely dentate or crenate, at least in upper third ................................................................. 2

1’. Leaflets entire....................................................................................................................................... 3

2. Leaflets 5; lamina narrowly elliptic, long acuminate, thin and papery; rainforest tree.......................... ....................................................................................................................................... 13. V. oxycuspis

2’. Leaflets 1–3(–5); lamina obovate, rounded at tip, thick and coriaceous; savanna shrub....................... .........................................................................................................11a. V. madiensis subsp. madiensis

3. Cymules arranged in thyrses, often grouped in panicles; fruit globose, 5–9 mm in diameter............. 4

3’. Cymules arranged in compound dichasia; fruit ovoid, (7–) 10–40 mm long ....................................... 7

4. Leaflets 5; secondary veins 7–9 on each side; thyrses mostly grouped in a terminal panicle ............. 5

4’. Leaflets 3; secondary veins 4–5 on each side; thyrses mostly in the axils of leaves .. 1. V. agelaeifolia

5. Fruit with golden-yellow glandulose outer layer exfoliating at maturity; fruiting calyx cupuliform, clasping base of fruit .................................................................................................... 2. V. buchananii

5’. Fruit brownish, without a golden-yellow outer layer; fruiting calyx patelliform, not clasping fruit base ...................................................................................................................................................... 6

6. Twigs pubescent, solid, not myrmecophilous, quickly becoming terete; leaflets pubescent on both surfaces ......................................................................................................... 6. V. discoideoglandulosa

6’. Twigs glabrous to puberulous, hollow, inhabited by ants, strongly quadrangular; lower surface of leaflets almost glabrous................................................................................................ 17. V. thyrsiflora

7. Ovary hirsute-tomentose ...................................................................................................................... 8

7’. Ovary glabrous, glandulose, or, rarely, with short stiff hairs at top ................................................... 13

8. Leavesin verticilsof three; leaflets almostglabrous exceptciliate domatia; fruit <9(–10) mm long.. ...................................................................................................................................... 7. V. djumaensis

8’. Leaves opposite (very rarely verticillate); leaflets glabrous or pubescent; fruit> 9 mm long ............ 9

9. Leaflets glabrous, shiny above, coriaceous, petiolulate, mostly rounded at tip (more rarely with a short blunt acumen).................................................................................................................... 8. V. doniana

9’. Leaflets variously pubescent, dull, petiolulate or sessile, rounded or acuminate .............................. 10

10. Leaflets markedly cuspidate or acuminate; upper surface of lamina glabrous, except on main vein.... .............................................................................................................................................................11

10’. Leaflets rounded to obtuse at tip; upper surface of lamina pubescent ............................................... 12

11. Peduncle 0.5–3 cm; cyme few-flowered, branched at 2 to 4 nodes, much shorter than subtending leaf, branches ochraceous pubescent; leaflet upper surface blackish-green in herbarium, smooth; lower surface with short ochraceous hairs on veins; bracts narrowly elliptic, discolorous, ochraceous tomentose beneath.......................................................................................................... 9. V. ferruginea

11’. Peduncle 5–11 cm; cyme very lax, branched at 5 to 7 nodes, equalling subtending leaf; leaflet upper surface green to brownish in herbarium, very slightly scabridulous; lower surface softly tomentellous; bracts linear, concolorous................................................................................................ 5. V. cuspidata

12. Corolla 10–15 mm long, with long-protruding stamens; inflorescence few-flowered, 2–4 cm wide, lax; lower surface of leaflets yellowish pubescent, the indumentum not masking areolae .......................... .................................................................................................................................... 12. V. mombassae

12’. Corolla 6–10 mm long, stamens not protruding; inflorescence many-flowered, 3–10 cm wide, cymules often compact; lower surface of leaflets densely greyish floccose-velvety, the indumentum masking areolae ................................................................................................................................. 14. V. payos

13. Calyx, pedicels and petiole with long patent fulvous to ferrugineous hairs, most of them exceeding 0.5 mm; leaflets with soft spreading hairs on lower surface and shorter erect hairs on upper surface ........ ...................................................................................................................................... 4. V. congolensis

13’. Calyx, pedicels and petiole without patent fulvous to ferrugineous hairs, puberulent or tomentose; leaflets almost glabrous to pubescent................................................................................................. 14

14. Leaves glabrous (except for a few short hairs on lower surface of mid-vein); inflorescence <5 cm (including peduncle), few-flowered; corolla ≥ 10 mm long, orange, more rarely white ....................... ............................................................................................................................ 16. V. rubroaurantiaca

14’. Leaves more or less pubescent; inflorescence 5–20 cm long, many-flowered, corolla <10 mm long, white, purplish or bluish .................................................................................................................... 15

15. Flowering calyx obliquely subtruncate, slightly zygomorphic, with obsolete teeth (<0.5 mm long); inflorescence branches and calyx with a very short dense tomentellum of greyish-beige to ochraceousbeige curly hairs; secondary veins 15–25 pairs; tertiary veins prominent on lower surface (but often masked by indumentum), forming a conspicuous ladder-like pattern; leaflets widest at the middle or below the middle; petiolules 10–30 mm; bracts discolorous, beige-ochraceous tomentose on lower surface, glabrous on upper surface.................................................................................... 10. V. fischeri

15’. Flowering calyx not zygomorphic, with well-developed teeth; inflorescence branches and calyx puberulent or pubescent, but not densely beige tomentose; secondary veins 8–20 pairs; tertiary veins not forming aconspicuous ladder pattern (except V. ciliata ); leaflets generally widestabove the middle, sessile or petiolulate; bracts not markedly discolorous...................................................................... 16

16. Upper surface of leaflets markedly scabrid, with reticulum prominulent; leaflets very coriaceous; calyx 2.5–3.5 mm long with broadly triangular teeth; corolla 5–10 mm long, bluish or mauve with white throat; savanna shrub......................................................... 11b. V. madiensis subsp. milanjiensis

16’. Upper surface of leaflets not scabrid (or slightly so), with reticulum not prominent; leaflets not remarkably coriaceous; calyx 1.5–2.5 mm long, with narrow triangular teeth; corolla <5 mm long, whitish-cream sometimes with a blue tinge in lower lip (corolla unknown in V. cuspidata ); trees of woodlands and forests........................................................................................................................ 17

17. Leaflets softly tomentellose on veins and reticulum beneath, without conspicuous glands; inflorescence branches and petiole tomentellose; leaflets narrowly elliptic to oblanceolate, 2.5–3.5 cm wide, abruptly contracted into a short acumen; petiolule 3–17 mm; flowers unknown; dry woodland tree................................................................................................................................... 5. V. cuspidata

17’. Leaflets only sparsely puberulous on main veins beneath, conspicuously yellow gland-dotted; inflorescence branches and petiole puberulent to almost glabrous; leaflets 3–6.5 cm wide, variable in shape; rainforest trees......................................................................................................................... 18

18. Leaflets spathulate, broadly rounded at tip, cuspidate; petiolules 0–2(–3) mm; secondary veins 9–12 pairs; calyx with yellowish-fulvous hairs, without conspicuous glands; young twigs with golden yellow hairs .......................................................................................................................... 3. V. ciliata

18’. Leaflets elliptic or obovate, with a long fine acumen (5–20 mm); petiolules 5–25 mm; secondary veins 10–20 pairs; calyx pubescent, with conspicuous golden yellow glands; young twigs puberulent, without long golden yellow hairs.................................................................................... 15. V. rivularis