(6) 
2. Lemna.—Perigonium compressed, grow- 
ing out of the margin of a thallus. 
Aquatic. 
3. Scirpus.—Glumaceous. Spikelets imbri- 
cate from all sides. Inferior glume 
(1-2) sterile, but not smaller than the 
rest. Perigonial bristles not exserted. 
Fruit, a nutlet, apiculate by the persist- 
ent base of the style. Aquatic. 
4. Fraxinus. —Ovary 2-celled, laterally 
compressed. Fruit, a samara, Tree. 
5. Acena.—Perigonium lobes valvate. Fruit 
an akene enclosed in the perigonium. 
Style terminal. 
- 
Alchemilla.—Perigonium urceolate, brac- 
teolate, not spinose. Akene enclosed in 
the perigonium. Style lateral. 
B. Floral parts complete, inferior, regular. 
1. Fraxinus.—Fruit, a samara. Tree. 
2. Lepidium.—Fruit, a silicula, sad 
compressed. 
C. Floral parts complete, inferior, irregular. 
a. Ovary entire. 
1. Veronica.—Calyx herbaceous 4-parted. 
Ovary 2-celled. Fruit, an emarginate 
capsule. Leaves opposite. 
