Leptolaena

Schatz, George E., Lowry Ii, Porter P. & Wolf, Anne-Elizabeth, 2001, Endemic families of Madagascar. VII. A synoptic revision of Leptolaena Thouars sensu stricto (Sarcolaenaceae), Adansonia (3) 23 (2), pp. 171-189 : 173-174

Key to the species of the Leptolaena s.s.

1.Leaves small, the largest blades usually <2 cm long (occasionally to 4.5 cm), rhombic; inflorescences composed of 1-5 flowers ................................................................ 7. L. pauciflora

1’.Leaves larger, the largest blade> 3 cm long, lanceolate, obovate or narrowly to inflorescences composed of 7-50 flowers (2-8 in L. masoalensis ) ................................................................ 2

2. Leaf apex obtuse to rounded, sometimes emarginate ................................................................................ 3

2’. Leaf apex acute to acuminate .................................................................................................................... 4

3.Involucre urceolate, 3 mm tall, covered with dense granular ferruginous 1-1.5 mm beyond involucre; leaves narrowly to broadly elliptic, secondary veins (8-)11-13 per side ............ ........................................................................................................................................ 3. L. delphinensis

3’.Involucre ellipsoid to oblong, 7 mm tall, covered with sparse, short white indumentum; included within involucre; leaves elliptic to slightly obovate, secondary veins usually 8 per side .................. ........................................................................................................................................ 5. L. masoalensis

4. Leaves sparsely to moderately sericeous below, with both short appressed trichomes and longer slightly raised trichomes often exceeding 1 mm long (older leaves occasionally subglabrous), margins distinctly revolute .............................................................................................................................. 8. L. raymondii

4’.Leaves glabrous below or with indumentum restricted to the midvein, margins weakly sometimes minutely thickened .................................................................................................................. 5

5. Leaf blades with evident indumentum on the midvein below .................................................................. 6

5’. Leaf blades completely glabrous (rarely a few trichomes at the base of the midvein below) ........................ 7

6.Involucre usually <3 mm tall, densely golden yellow granular farinose, rounded at peduncle 1 mm long; petals 7-9 × 1-1.5 mm; leaves lanceolate to ovate, apex distinctly long cuspidate ...... ............................................................................................................................................ 2. L. cuspidata

6’.Involucre 3-3.5 mm tall, densely ferruginous granular farinose, usually also with slightly chomes 0.5 mm long, especially in the lower portion, evenly tapering to a cuneate base, with an indistinct peduncle <0.5 mm long; petals 10.5-12 × 1.5-2 mm; leaves ovate to broadly ovate, apex acute to acuminate, rarely cuspidate .............................................................................................................. 4. L. gautieri

7.Leaves narrowly ovate, usually strongly falcate and inequilateral, often drying reddish acuminate to cuspidate, largest blades 2.5-4.5(-5.5) cm long; sepals at anthesis equal to involucre teeth or exceeding them by <0.5 mm .............................................................................................. 1. L. abrahamii

7’.Leaves elliptic, usually equilateral to somewhat inequilateral, rarely a few somewhat falcate, to olive green, largest blades greater than (3-) 5.5 cm long; sepals at anthesis exceeding the involucre teeth by (0.8-) 1-1.8 mm .................................................................................................................. 6. L. multiflora