Scolopia, Schreb.

Applequist, Wendy L. & Schatz, George E., 2016, A synoptic revision of the Malagasy species of Scolopia Schreb. (Salicaceae, Scolopieae), Adansonia 38 (1), pp. 99-115 : 101

KEY TO THE MALAGASY SPECIES OF SCOLOPIA SCHREB.

1. Shrub or small tree, usually spiny; inflorescences 1-flowered; W, S, or extreme N or SE Madagascar, in dry to transitional forests or bush .......................................................................................................................... 2

— Tree or seldom a large shrub, never spiny; inflorescences few- to several-flowered; E to extreme N or SE Madagascar, usually in humid or littoral forests .................................................................................................... 6

2. Ovary pubescent; glandular disk virtually absent; extreme SE and SW ...... 8. S. meridionalis Capuron & Sleumer

— Ovary glabrous; glandular disk present, with small inconspicuous glands .................................................... 3

3. Spines few or absent; leaves (2-)3-6(-8) cm, elliptical to subovate, the apex short-acuminate to subacute; NW Madagascar ............................................................................................ 5. S. inappendiculata H.Perrier

— Spines usually present; leaves 1-2.5 cm, obovate to oblanceolate-oblong or suborbicular, the apex obtuse and often crenate; S or extreme N Madagascar ................................................................................................... 4

4. Leaves sometimes suborbicular; secondary veins 2-4 pairs, more conspicuous than tertiary veins, usually slightly curving and forming relatively broad angle with midrib; abaxial surface of sepals glabrous; S Madagascar ....................................................................................................................... 12. S. spinescens Sleumer

— Leaves always much longer than broad; secondary veins several pairs, very fine, straight and forming a narrow angle with midrib; abaxial surface of sepals minutely pubescent; extreme N Madagascar ............................. 5

5. Leaves narrowly oblong-obovate to oblong-oblanceolate, (3-)4-6(-8) mm wide; stamens 40-60 ..................... ....................................................................................................... 11. S. septentrionalis Capuron & Sleumer

— Leaves obovate, 7-12 mm wide; stamens 80-120 ...................................... 1. S. calcicola Capuron & Sleumer

6. Adaxial surface of sepals and petals appressed-puberulent; perianth strongly accrescent in fruit; N Madagascar .......................................................................................................................... 7. S. manongarivae H.Perrier

— Adaxial surface of sepals and petals glabrous; perianth slightly or not accrescent .......................................... 7

7. Leaves variable in shape and size, at maturity usually> 6.5 cm long except in S. delphinensis , sp. nov. (where smaller leaves are common); pedicels>(3-) 4.5 mm long in flower,> 4.5 mm long in fruit; stamens 80-100 or more .... 8

— Leaves relatively small, at maturity <6.5 (in S. montana to 7.5) cm long; pedicels <3 mm long in flower, <4.5 mm (very rarely to 8 mm) long in fruit; stamens 20-50(-60) ............................................................................ 11

8. Leaves narrowly elliptical to narrowly oblong-elliptical or oblanceolate (rarely elliptical), (2.5-)3.5-7.3(-9.3) × 1.3-2.9(-4.7) cm, with petiole 3-6(-8) mm long; apex acute to rounded (rarely obtuse or cuspidate); endemic to extreme SE near Fort-Dauphin ...................................... 2. S. delphinensis Appleq. & G.E.Schatz , sp. nov.

— Leaves elliptical to oblong-elliptical, sometimes somewhat obovate, or broadly elliptical, usually with most leaves> 7.3 cm long or> 2.9 cm wide, if smaller then with petiole at least 6 (rarely 5) mm long; apex variable, sometimes acuminate; widely distributed .................................................................................................... 9

9. Leaves elliptical to broadly elliptical, (5.2-)7.5-12.4(-14) × (3.2-)3.8-7.7(-9.6) cm, usually less than twice as long as broad; apex cuspidate (rarely rounded or emarginate); base convex, usually broadly so, to rounded; littoral forests .............................................................................................................. 6. S. madagascariensis Sleumer

— Leaves elliptical to oblong-elliptical or narrowly elliptical (to somewhat obovate), normally <11.5 cm long and more than twice as long as broad; apex variable, often mostly acuminate or mostly rounded; base convex, usually acutely (infrequently cuneate to attenuate) .......................................................................................... 10

10. Leaves usually drying brown (rarely green, mostly from near-coastal habitats); apex acuminate to long-cuspidate (rarely to obtuse or rounded); usually low- to mid-elevation humid forests, rarely coastal ........... 4. S. hazomby H.Perrier

— Leaves normally drying pale, greenish to olive or gray-green; apex rounded to obtuse (infrequently cuspidate, emarginate); littoral and sublittoral forests ................................................................ 10. S. orientalis Sleumer

11. Leaves ovate to elliptical (lanceolate) with a usually long-caudate apex and rounded base .... 14. S. thouvenotii H.Perrier

— Leaves variable in shape, but not primarily ovate nor with a caudate apex ................................................. 12

12. Leaves broadly elliptical (to elliptical or slightly ovate or obovate), usually less than twice as long as broad; apex rounded (obtuse, emarginate); base convex and obtuse (to round) ....................... 13. S. taimbarina H.Perrier

— Leaves obovate (to oblanceolate) or narrowly oblong to oblanceolate-oblong, usually at least twice as long as broad; apex mostly short-cuspidate or mostly rounded; base cuneate (to attenuate) ................................... 13

13. Leaves obovate (to oblanceolate), (1.7-)2.5-5.3(-6) × (0.9-)1.2-2.3(-3.2) cm, with apex usually rounded (to somewhat obtuse or emarginate); littoral and sublittoral forests ............................ 3. S. erythrocarpa H.Perrier

— Leaves narrowly oblong to oblanceolate-oblong, 3.5-7.5 × 1.4-3 cm, with apex short-cuspidate to rounded (seldom obtuse); low- to moderately high-elevation humid forests .............................. 9. S. montana Sleumer