Aspidostemon Rohwer & Richter

Werff, Henk Van Der, 2006, A revision of the Malagasy endemic genus Aspidostemon Rohwer & Richter (Lauraceae), Adansonia (3) 28 (1), pp. 7-44 : 10-13

Genus Aspidostemon Rohwer & Richter

Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 109: 71 (1987).

Cryptocarya subg. Hexanthera Kosterm. , Bulletin du Jardin botanique de l’État 27: 174 (1957). — Type: not designated.

Cryptocarya subg. Trianthera Kosterm. , Bulletin du Jardin botanique de l’État 27: 174 (1957). — Type: not designated.

TYPE. — Aspidostemon perrieri (Danguy) Rohwer.

DESCRIPTION

Trees. Leaves opposite, evenly distributed along the branches, pinnately veined, entire, domatia lacking. Inflorescences axillary, shorter than the leaves, usually few-flowered, paniculate or racemose, usually with scars of fallen bracts at the base. Flowers bisexual, small, to 4 mm in diameter, elongate, globose or depressed globose, white or light green, in a few species stamens red; tepals 6, in 2 series of 3, equal, erect, rarely spreading; stamens 3 or 6, representing the outer whorl or the 2 outer whorls, columnar or tepaloid, 2-locellate, the locelli introrse or apical, staminodia of whorl III conspicuous, columnar, often with the apex shield-like and enlarged, free or fused into a shield-like structure, 2 glands present at the base of staminodia of whorl III; staminodia of whorl IV small, stipitate or absent. Hypanthium short or deep. Pistil slender, glabrous, immersed in the hypanthium. Fruit completely enclosed in the enlarged hypanthium, floral parts persistent on top of the fruit.

DISTRIBUTION AND HABITAT

A genus of 28 species, all endemic to Madagascar and restricted to wet forests from sea level to about 1000 m altitude .

KEY TO SPECIES OF ASPIDOSTEMON ROHWER & RICHTER

1. Flowers with 3 fertile stamens .................................................................................... 2

— Flowers with 6 fertile stamens .................................................................................. 17

2. Staminodes of whorl III apically papillose or pubescent ............................................. 3 — Staminodes of whorl III apically smooth ................................................................... 7

3. Staminodes of whorl III fused into a shield-like plate with or without a raised center

(umbonate) ................................................................................................................ 4 — Staminodes of whorl III free; the center of flower not umbonate ................................ 6

4. Staminodes of whorl III apically pubescent ........................................ 28. A. trichandra — Staminodes of whorl III apically papillose .................................................................. 5

5. Flowers globose, 1-1.4 mm in diam.; terminal buds pubescent ......... 9. A. glandulosum — Flowers depressed globose, wider than long, 2-3 mm in diam.; center of the flower raised,

umbonate; terminal buds glabrous ....................................................... 26. A. synandra

6. Locelli apical; fruits to 2.4 cm long, longitudinally ribbed ........................ 16. A. lucens — Locelli introrse; fruits to 3.7 cm long, smooth ............................ 18. A. manongarivense

7. Inflorescences pubescent, the indument covering most of the surface ......................... 8 — Inflorescences glabrous or sparsely pubescent, clearly most of the surface visible ....... 10

8. Flowers disc-shaped, much wider than long, 3-3.5 mm in diam.; leaves 4-6 cm wide

.................................................................................................... 11. A. humbertianum — Flowers globose or conical, 1.5-2.5 mm in diam.; leaves to 3 cm wide ...................... 9

9. Staminodia of whorl III free; leaf apices blunt or obtuse, flat ............... 6. A. conoideum

— Staminodia of whorl III fused, shield-like; leaf apices acuminate, the acumen 4-8 mm

long or the apices inrolled ................................................................. 2. A. antongilense

10. Terminal or vegetative buds appressed pubescent; locelli of the outer three stamens lateral; base of the staminodes of whorl III and the rim at the top of the perianth pubescent .... .......................................................................................................... 19. A. masoalense

— Terminal or vegetative buds glabrous or with a fringe of hairs; locelli introrse or apical; base of the staminodes of whorl III and perianth rim glabrous or pubescent in A. andohahelense ................................................................................................................... 11

11. Tepals cucullate, thickened and bulging outwards, the flower seen from above 6-lobed

........................................................................................................... 27. A. trianthera — Tepals not or scarcely bulging outwards, the flower not appearing 6-lobed when seen from

above ........................................................................................................................ 12

12. Flowers wider than long ........................................................................................... 13 — Flowers as wide as long or longer than wide ............................................................. 16

13. Locelli lateral, scarcely visible from above ....................................... 1. A. andohahelense — Locelli apical, readily visible from above ................................................................... 14

14. Leaves chartaceous or papyraceous, dull above; reticulation on lower surface immersed ... 15 — Leaves subcoriaceous, smooth and shiny above; reticulation weakly raised on lower surface

...................................................................................................... 20. A. microphyllum

15. Pedicels 4-5 mm long; outer tepals bulging at the the base ...... 15. A. longepedicellatum — Pedicels 1-2 mm long; outer tepals similar in size and shape to the inner ones ...............

............................................................................................................. 21. A. occultum

16. Inflorescences sparsely puberulous; staminodes of whorl III fused, shield-like ...............

.............................................................................................................. 4. A. capuronii — Inflorescences glabrous; staminodes of whorl III free ........................ 25. A. reticulatum

17. Inflorescences sparsely to rather densely pubescent ................................................... 18 — Inflorescences glabrous ............................................................................................. 25

18. Leaves 15-30 cm long; terminal buds pubescent; outside of tepals pubescent ................

..................................................................................................... 17. A. macrophyllum — Leaves less than 15 cm long or if occasionally exceeding 15 cm, then terminal buds and

tepals glabrous .......................................................................................................... 19

19. Flowers disc-shaped, wider than long; tepals glabrous ............................................... 20 — Flowers conical or globose, about as wide as long; staminodes of whorl III free, columnar,

somewhat widened towards the tip; tepals glabrous or pubescent ............................. 22

20. Leaves 12-20 cm long; inflorescences 3-7 cm long ................................... 13. A. insigne — Leaves less than 12 cm long; inflorescences c. 1.5 cm long ........................................ 21

21. Terminal or vegetative buds pubescent; locelli apical, readily seen ....... 8. A. fungiforme — Terminal or vegetative buds with a fringe of hairs, otherwise glabrous; locelli apical-lateral,

small, difficult to see ....................................................................... 1. A. andohahelense

22. Staminodes III apically densely papillose .................................... 18. A. manongarivense — Staminodes III apically smooth ................................................................................ 23

23. Flowers and pedicels glabrous or nearly so; leaves elliptic to broadly elliptic ..................

................................................................................................................ 14. A. litorale — Flowers and pedicels pubescent; leaves oblong to elliptic .......................................... 24

24. Terminal or vegetative buds glabrous; leaves coriaceous, the reticulation raised on the lower leaf surface; inflorescences with short, erect, reddish hairs, the surface partially visible ... ....................................................................................................... 7. A. dolichocarpum

— Terminal or vegetative buds densely pubescent; leaves (firmly) chartaceous, the reticulation immersed on the lower leaf surface; inflorescences densely pubescent, the indument consisting of brown, ascending hairs ......................................................... 10. A. grayi

25. Leaves to 6.5 cm long, the tip obtuse or emarginate; tepals and stamens spreading at anthesis; fertile stamens with a short filament ...................................... 22. A. parvifolium

— Leaves longer or if 5-7 cm long, the tip acuminate or apiculate, not obtuse; tepals and stamens erect at anthesis, not spreading; stamens sessile, without a short filament .... 26

26. Staminodes of whorl III fused of nearly so, the apices flattened and forming a shield-like

cover over the center of the flower ............................................................................ 27 — Staminodes of whorl III free, not forming a shield-like cover over the center of the flower

................................................................................................................................. 28

27. Leaves coriaceous, the tip bluntly acuminate, flat; stamens and staminodia III papillose

....................................................................................................... 23. A. percoriaceum — Leaves papyraceous, the tip sharply acuminate, inrolled; stamens and staminodia III

smooth ................................................................................................. 21. A. occultum

28. Leaf apices acuminate; acumens 5-15 mm long ........................................................ 29 — Leaf apices bluntly acute or apiculate ....................................................................... 31

29. Leaves papyraceous; locelli apical .......................................................... 21. A. occultum — Leaves firmly chartaceous or coriaceous; locelli introrse ............................................ 30

30. Acumen c. 5 mm long; leaves often drying conduplicate ........................ 24. A. perrieri — Acumen 10-15 mm long; leaves drying flat .......................................... 5. A. caudatum

31. Tertiary venation on lower leaf surface immersed; leaves drying flat .......................... 32 — Tertiary venation on lower leaf surface raised; leaves often drying conduplicate .............

............................................................................................................... 24. A. perrieri

32. Leaf apices apiculate; leaves slightly obovate; stamens and staminodia pubescent near the base .................................................................................................... 3. A. apiculatum

— Leaf apices bluntly acute; leaves elliptic to narrowly elliptic; stamens and staminodia glabrous ............................................................................................. 12. A. inconspicuum