KEYS TO GENERA 21 
5. Apex of leaves rounded and usually notched. 
6, Petioles usually about 2 or more centimeters in length; leaves, 
stems, and fruits densely covered with small round scales. 
Camptostemon, page 34 
6. Petioles 1 centimeter or less in length. 
7. Fruits shaped like a banana except that the tips are sharply 
PDQUOIGEM el. ko: cos sheihl nc eee ee ren ae Aegiceras, page 66 
7. Fruits not shaped like a banana... Lumnitzera, page 62 
Key to the genera of mangrove-swamp plants. 
[Based on floral characters. ] 
1. Plant without flowers or seeds, reproduced by means of spores. 
Family 1, Polypodiaceae; Acrostichwm. 
1. Plants with flowers that produce seeds. 
2. Cotyledon one; leaves parallel-veined.............-.0...... Family 2, Palmae. 
SeVILMNGrCEL SPINY GPUMK fo. es oe Oncosperma. 
Bo WothouL trunivand without spines... 005 0... Nipa. 
2. Cotyledons two; leaves netted-veined. 
3. Corolla none. 
A, Ovary Anterior. 22-52 Family 10, Combretaceae; Lumnitzera. 
4. Ovary superior. 
5. Flowers dioecious; plants with milky juice. 
Family 4, Euphorbiaceae; Excoecaria. 
5. Flowers monoecious; plants without milky juice. 
Family 7, Sterculiaceae; Heritiera. 
3. Calyx and corolla both present; the corolla of distinct and separate 
petals. 
4, Ovary superior. 
5. Stamens numerous, more than twice as many as the petals. 
6. Filaments united, stamens on the outside of a column. 
Family 6, Bombacaceae; Camptostemon. 
6. Filaments free...................... Family 5, Tiliaceae; Brownlowia. 
5. Stamens few, never more than twice as many as the petals; 
inside of small cup-shaped tube. 
Family 3, Meliaceae; Xylocarpus. 
4, Ovary inferior. 
5. Stamens numerous, many times as many as the petals. 
6. Flowers small; calyx lobes imbricate in bud; leaves usually 
with glandular dots............ Family 11, Myrtaceae; Osbornia. 
6. Flowers large; calyx lobes valvate in bud; leaves not gland- 
ular dotted................ Family 8, Sonneratiaceae; Sonneratia. 
5. Stamens usually twice as many as the petals. 
Family 9, Rhizophoraceae. 
Gre chats youre, ees AMS El. een ee cy ee .. Rhizophora. 
Gi Betalste dives Or aSix 2 s.2 oats Eis 5 21S lel hee Ceriops. 
6: Petalsmeiehts to sfourteens ss. aes ee ee Bruguiera. 
3. Calyx and corolla both present; the petals more or less united. 
4. Ovary superior. 
5. Stamens opposite the lobes of the corolla, as many as the lobes. 
Family 12, Myrsinaceae; Aegiceras. 
5. Stamens as many as the lobes of the corolla in regular flowers 
and alternate with the lobes, or sometimes fewer in irreg- 
ular flowers. 
