SCIENTIFIC KEY TO THE GENERA

1Seeds without endosperm.
1'Seeds with endosperm.
2Condyle obsolete or septiform. TILIACOREAE (except Tiliacora).
2'Condyle hollow with a central aperture on both sides of endocarp. (MENISPERMEAE p.p.)
3Condyle obsolete. Seed straight, broadly ellipsoidal. Stamens often more than 6 and ± connate.
3'Condyle an elongate septum around which the seed is sharply bent. Stamens 6, free.
4Drupe with style-scar below the apparent apex. Sepals all free.
4'Drupe with style-scar near base. Inner sepals connate in a fleshy tubular calyx. Stamens c. 18-24, connate in a conical cluster
5Drupes not narrowed at base into a stipe, 3-6 on a ± globose carpophore. Endocarp usually papyraceous to crustaceous and ± smooth, sometimes thick, bony and verrucose. Stamens 6-18, usually connate for most of length; connective not prolonged
5'Drupes narrowed at base into a stipe, 5-10 radiating from the margin of a disciform carpophore. Endocarp thick and bony, dorsally covered with a coarse open network of ridges, ventrally smooth. Stamens 9, 3 inner free surrounded by 6 slightly joined at base; connective prolonged into a tongue
6Inner sepals valvate. Leaves penninerved
6'Sepals all imbricate. Leaves triplinerved
7Drupe with style-scar terminal. Embryo with foliaceous cotyledons. TINOSPOREAE (incl. Fibraureeae).
7'Drupe with style-scar near base or on one side.
8Petals 3 or 6.
8'Petals 0. Endocarp subellipsoidal, smooth with condyle forming a narrow ventral groove
9Stamens free.
9'Stamens united in a peltate synandrium. Endocarp spiny, the condyle forming a ventral concavity or an enclosed inflated chamber
10Endocarp globose, covered with series of branched spines. Condyle clavate, 2-chambered, deeply intruding into the seed cavity. Stamens with flattened elliptic filaments broader than the anthers
10'Endocarp not spiny. Stamens with ± terete filaments not broader than the anthers.
11Endocarp knobbly, papillose or smooth with a ventral aperture or elongate depression; condyle sometimes forming a ventral cavity. Endosperm usually ventrally ruminate. Plant without a laticiferous system. Leaves not striate above
11'Endocarp rugose to rugulose, strongly compressed dorsiventrally without a ventral aperture or depression; condyle obsolete. Endosperm not ruminate. A laticiferous system present throughout the plant. Leaves finely and closely striate above
12Embryo with foliaceous, divaricate cotyledons. Seed broadly ellipsoidal or deeply cup-shaped. Petals 0. COSCINEAE.
12'Embryo elongate with narrow, semi-terete or flattened cotyledons lying close together. Seed elongate, strongly curved, ± horseshoe-shaped. Petals present, at least in male flowers.
13Condyle obsolete. Seed broadly ellipsoidal. Carpophore clavate. Anthers 9-12 in a sessile cluster
13'Condyle deeply intruding into the seed-cavity. Seed deeply cup-shaped.
14Condyle deeply 2-lobed, hollow. Carpophore shortly branched below the drupes. Anthers 30-35 in a stalked cluster. Inflorescence in a panicle
14'Condyle ± peltate, unlobed. Carpophore globose. Stamens 6, the outer 3 free with 1-locular introrse anthers, the inner 3 with connate filaments and 2-locular latrorse anthers. Inflorescence a raceme of peduncled balls of flowers
15Endosperm ruminate. Condyle septiform (TILIACOREAE.p.p.)
15'Endosperm not ruminate. Condyle usually obovate in outline with the seed curved around its margin, sometimes hollow and 1-2-chambered. MENISPERMEAE (except Pachygone).
16Sepals spirally arranged, imbricate, variable in number, 7-12. Stamens 9-40, free or connate. Carpels 2-3 (Mal. spp.)
16'Sepals in whorls of 3 or in one united whorl.
17Carpels 3-6. Stamens free or only filaments connate.
17'Carpel 1. Stamens completely connate in a peltate synandrium with the anthers horizontal around the margin.
18Inner sepals valvate. Condyle hollow, 2-chambered
18'Inner sepals imbricate. Condyle ± lamelliform.
19Petals thick and fleshy, much larger than the sepals. Stamens with connate filaments
19'Petals smaller than sepals or absent in female flowers. Stamens free.
20Petals entire, sometimes absent in female flowers.
20'Petals bifid or emarginate. Endocarp dorsally verruculose or transversely ridged, with an aperture on both lateral faces leading to a lateral cavity
21Condyle obovate to rotund in outline. Inflorescences axillary, cymes or thyrses.
21'Condyle elongate, very narrow with the seed sharply bent around it. Inflorescences from old woody stems (Mal. spp.), long racemes of cymes (Mal. spp.)
22Petals absent in female flowers. Anthers dehiscing with transverse ± introrse slits, the cells separated abaxially by the thickened connective. Endocarp with an entire dorsal median wing or ridge and prominent lateral curved or cucullate crests bordering the condyle, the dorsal region smooth (Mal. spp.)
22'Petals present in female flowers. Anthers dehiscing with longitudinal latrorse slits, the cells parallel and close together. Endocarp without a dorsal median wing or ridge and lateral crests, dorsally covered with short pointed processes
23Female inflorescences with accrescent bracts (Mal. sp.). Flowers 4-merous. Petals connate
23'Female inflorescences without accrescent bracts.
24Inflorescences thyrsoid or pseudoracemose. Condyle hollow, 1-chambered. Flowers 4-merous. Petals free or connate
24'Inflorescences composed of umbelliform cymes or disciform capitula. Condyle lamelliform. Flowers 3-4-merous. Petals free