Buxus

Schatz, George E. & Lowry Ii, Porter P., 2002, A synoptic revision of the genus Buxus L. (Buxaceae) in Madagascar and the Comoro Islands, Adansonia (3) 24 (2), pp. 179-196 : 181

Key to the species of Buxus in Madagascar and the Comoro Islands

1. Leaves with 15-23 pairs of secondary veins, largest blades (6.5-)8-11 × (2.8-) 4.2-5 cm; fruits 20-30 mm tall, mesocarp c. 5-8 mm thick .............................................................................................. 6. B. macrocarpa

1’. Leaves with no more than 10(-14) pairs of secondary veins or the venation obscure, largest blades <7 × 2.5 cm; fruits <10 mm tall, mesocarp <1 mm thick ................................................................................ 2

2. Leaves linear, 1.4-3.7 × 0.09-0.3 cm ................................................................................ 5. B. itremoensis

2’. Leaves broader, narrowly elliptic or lanceolate to ovate, elliptic, rhombic or obovate ................................ 3

3. Leaves obovate to narrowly obovate, broadest above the middle, apex usually rounded to emarginate, occasionally obtuse .................................................................................................................................. 4

3’. Leaves lanceolate, ovate, elliptic or rhombic, broadest at or below the middle, apex acute to cuspidate (rarely rounded) .................................................................................................................................................. 6

4. Largest leaves> 4 cm long, lower portion of the midrib on upper surface with dense, short, erect indumentum, margins distinctly revolute .................................................................................................. 3. B. capuronii

4’. Leaves <3.5 cm long, midrib glabrous above, margins flat to weakly revolute .......................................... 5

5. Leaves glaucous, especially when young, apex rounded to occasionally obtuse, venation obscure ................ .............................................................................................................................................. 2. B. calcarea

5’. Leaves greenish, apex rounded and usually emarginate, secondary and tertiary venation visible on upper surface..................................................................................................................................4. B. humbertii

6. Leaves lanceolate to narrowly elliptic or narrowly lanceolate, (2.5-)3-10 times as long as wide, apex narrowly acute to acuminate or long cuspidate ........................................................................................................ 7

6’. Leaves ovate, elliptic or rhombic, 1.5-2.5(-3) times as long as wide, apex acute (rarely rounded) .............. 8

7. Largest leaves 3.4-3.6 cm long, dull above, margins distinctly revolute; fruits 3.2-4 × 2.5-2.8 mm .............. ........................................................................................................................................ 1. B. angustifolia

7’. Largest leaves 4.2-8 cm long, shiny above, margins flat; fruits 5-7 × 4-5 mm ........................ 9. B. moratii

8. Plants completely glabrous; leaf blades flat, ovate to elliptic; littoral forest near sea level along E coast, mostly on sand, rarely to 600 m on Mayotte.......................................................................... 7. B. madagascarica

8’. Plants with minute, erect indumentum at least on the upper midrib toward the base of the leaves and on young twigs, often elsewhere as well; leaf blades usually corrugated, convex above on each side of the midrib, elliptic to rhombic; montane forest, 800-> 2000 m ............................................................ 8. B. monticola