Monoon Miq.

Turner, Ian M. & Utteridge, Timothy M. A., 2016, Whither Polyalthia (Annonaceae) in Peninsular Malaysia? Synopses of Huberantha, Maasia, Monoon and Polyalthia s. s., European Journal of Taxonomy 183, pp. 1-26 : 5-7

Monoon Miq.

Annales Musei Botanici Lugdunu-Batavi 2: 15 ( Miquel 1865). – Lectotype (designated by Saunders & Xue 2011: 236): Monoon lateriflorum (Blume) Miq.

Enicosanthum Becc ., Nuovo Giornale Botanico Italiano 3: 183 ( Beccari 1871). – Type: Enicosanthum paradoxum Becc.

Marcuccia Becc. , Nuovo Giornale Botanico Italiano 3: 181, t. 3 ( Beccari 1871). – Type: Marcuccia grandiflora Becc.

Griffithia Maingay ex King , Annals of the Royal Botanic Garden (Calcutta) 4: 8 ( King 1893), non Griffithia Wight & Arn. ( Wight & Arnott 1834). – Griffithianthus Merr., Philippine Journal of Science. Section C, Botany 10: 231 ( Merrill 1915). – Lectotype (designated by Merrill 1915: 231): Griffithia magnoliipetala Maingay ex King.

Woodiella Merr. , Journal of the Straits Branch of the Royal Asiatic Society 85: 187 ( Merrill 1922), non Woodiella Sacc. & P.Syd. ( Sydow 1899) . – Woodiellantha Rauschert , Taxon 31: 555 ( Rauschert 1982). – Type: Woodiella sympetala Merr.

Cleistopetalum H.Okada, Acta Phytotaxonomica et Geobotanica 47: 4 ( Okada 1996). – Type: Cleistopetalum borneense H.Okada.

Key to species of Monoon

1. Inflorescences on trunk or restricted to base of trunk ........................................................................ 2

– Inflorescences in leaf axils, or on twigs behind leaves (sometimes on branches) .............................. 6

2. Inflorescences borne on slender, flexible, branched basal flagellae ........................... M. hypogaeum

– Not so ................................................................................................................................................ 3

3. Inflorescences on stout, sparsely branching axes to at least 7 cm long ....................... M. praestigiosum

– Inflorescences on woody tubercles or much-branched axes less than 7 cm long ............................... 4

4. Inflorescences on woody tubercles .............................................................................. M. anomalum

– Inflorescences on much-branched axes ............................................................................................. 5

5. Leaves with 8–10 pairs of lateral nerves. Outer petals to 2.5 cm long, 0.5 cm wide. Monocarps with blunt beak ...................................................................................................................... M. borneense

– Leaves with c. 20 pairs of lateral nerves. Outer petal to 7 cm long, 2.5 cm wide. Monocarps with hard, sharp beak ................................................................................................................ M. congregatum

6. Leaves membranous. Inflorescences axillary, few-flowered (generally more than one). Sepals more than 8 mm long. Monocarps globose to ellipsoidal with rounded to slightly blunt apex ..................... ............................................................................................................................ M. membranifolium

– Leaves chartaceous to coriaceous. Inflorescences single to multi-flowered but if few-flowered and axillary then with sepals to 6 mm long. Monocarps ellipsoidal with blunt to beaked apex .............. 7

7. Young flowers with conical ‘bud’ stage; sepals more than 6 mm wide ............................................. 8

– Young flowers not with a conical ‘bud’ stage; sepals less than 6 mm wide ...................................... 11

8. Leaves with generally more than 20 pairs of lateral nerves. Flower pedicels more than 2.5 cm long .... ................................................................................................................................... M. macranthum

– Leaves with up to 20 pairs of lateral nerves. Flower pedicels to 1 cm long ...................................... 9

9. Twigs densely tomentose. Leaves with dense hairs on nerves below. Flower pedicel to 12 mm long ... ............................................................................................................................................ M. fuscum

– Twigs glabrescent. Leaves glabrous to glabrescent beneath. Flower pedicel generally more than 12 mm long ...................................................................................................................................... 10

10. Leaves to 17 cm long, 7 cm wide. Sepals much broader than long. Monocarps woolly hairy, apex rounded ............................................................................................................................ M. cupulare

– Leaves generally more than 17 cm long, 7 cm wide. Sepals about as long as broad. Monocarps not woolly hairy, apex beaked .................................................................................... M. magnoliiflorum

11. Petals distinctly longitudinally nerved. Monocarps subsessile, pale tomentose ....... M. pachyphyllum

– Petals not longitudinally nerved. Monocarps stipitate, glabrous to tomentose ............................... 12

12 (Leaves more than 24 cm long, 7 cm wide). Flowers borne distichously on sparsely branched hairy axes to 2 cm long, 4 mm thick. Petals thick and fleshy. Monocarps with stipe to 14 mm long, shorter than seed-bearing portion ........................................................................................... M. malayanum

– (Leaves generally smaller). Flowers borne in fascicles or on very short and relatively slender axes. Petals relatively thin. Monocarps with stipe generally exceeding length of seed-bearing portion ... 13

13. Flowering pedicel c. 0.5 mm thick; sepals to 2 mm long; petals to 3 mm wide .............. M. asteriellum

– Flowering pedicel at least 1 mm thick; sepals more than 2 mm long; petals 4 mm wide or more ... 14

14. Petals 4–5 mm wide. Monocarps densely short brown tomentose, stipe attachment eccentric. .............. ............................................................................................................................... M. xanthopetalum

– Petals 8 mm or more wide. Monocarps more or less glabrous, stipe attachment not eccentric ........ 15

15. Outer petals obovate (widest above midway), claw and blade distinct ........................................... 16

– Outer petals lanceolate to oblong-linear (widest at or below midway), little distinction between claw and blade ......................................................................................................................................... 17

16. Leaves obovate, reticulations obscure from above ..................................................... M.hookerianum

– Leaves elliptic, reticulations distinct from above ............................................................ M. glabrum

17. Leaves generally less than 20 cm long and 5 cm wide; lateral nerves 9–13 pairs. Sepals 3–4 mm long .. ................................................................................................................................. M. sclerophyllum

– Leaves generally more than 20 cm long and 5 cm wide; lateral nerves 14–15 pairs. Sepals to 3 mm long............................................................................................................................. M. lateriflorum