NYSSACEAE l 851 
and 4 or rarely 8 stamens: fruit globose-ovoid, 2 mm. long, each carpel strongly 2-keeled 
on the back and roughened. [M. scabratum Michx. ] 
In shailow ponds and ditches, Rhode Island to Missouri, Florida, Texas and Mexico. Also in 
Central America. Spring and summer. 
4. Myriophyllum heterophyllum Michx. Normally stout, 2-10 dm. long. Leaves 
of 2 kinds, the submersed ones crowded, more or less scattered, 1.5-5 cm. long, the hair- 
like segments in 6-10 pairs, the emersed leaves in whorls of 3's to 6’s, linear to oblong, 
sometimes varying to lanceolate or oblanceolate, sharply serrate: spikes erect or slightly 
nodding, 1-5 dm. long, simple or branched : flowers shorter than the bracts, the staminate 
about 3 mm. broad, with 4 oblong or ovate-oblong petals and 4-6 stamens : fruit 2-2.5 mm. 
long, each carpel 2-keeled on the back and slightly roughened. 
In ponds and slow-running water, Quebec to Minnesota, Florida, Texas and Mexico. Summer. 
Order 27. AMMIALES. 
Herbs, shrubs, trees or vines. Leaves alternate or opposite: blades mostly 
toothed, lobed, divided or compound. Flowers perfect, polygamous or dioecious, 
variously clustered, but commonly in umbels. Hypanthium present. Calyx of 
typically 5 relatively small sepals surmounting the hypanthium. Corolla typ- 
ically of 5 petals. Androecium of asmany stamens as there are sepals or petals. 
Gynoecium of 2 united carpels or rarely more, or sometimes 1-carpellary. Ovary 
inferior, 1-several-celled, sometimes surmounted by a stylopodium. Stigmas ter- 
minal or introrse. Fruit drupaceous or baccate, or dry and a cremocarp with 
smooth or spiny, ribbed or winged carpels. 
Fruit drupaceous or baccate: gynoecium 1-several-carpellary, if 2-carpellary, stigmas introrse. 
Ovule with a dorsal raphe: leaves mostly opposite; blades entire or merely toothed. 
Fam. 1. NYSSACEAE. 
* 
Ovule with a ventral raphe: leaves mostly alternate; blades lobed or com- 
Fam. 2. HEDERACEAE. 
. . pound. 2 
Fruit dry, a eremocarp: gynoecium 2-carpellary : stigmas terminal. Fam. 3. AMMIACEAE. 
FAMILY 1. NYSSÀCEAE Dumort. DoGgwoop FAMILY. 
Shrubs or trees, or rarely herbaceous shrubs. Leaves alternate or opposite, 
without stipules : blades mostly firm or leathery, usually entire. Flowers perfect 
or unisexual, in cymes or heads, sometimes subtended by involucres. Calyx of 
mostly 4-5 sepals. Corolla of 4-5 or rarely many, imbricated or valvate petals, 
inserted at the base of an epigynous disk, or wanting. Androecium of usually 
aS many stamens as there are petals and inserted with them. Filaments terete 
or flattened. Anthers attached at the base or the back. Gynoecium of 1-4 
united carpels. Ovary 1-4-celled, inferior. Styles united. Stigmas entire, lobed 
or cleft. Ovules solitary in each cavity or rarely 2, anatropous, pendulous, 
Fruit mostly a drupe, with an acid pulp, stones solitary or rarely 2, 1-4-celled. 
FRA with a membranous or thin-leathery testa. Endosperm fleshy. [Cornaceae 
ink. | 
Flowers dioecious or polygamo-dioecious : stigmas lateral. 
Stigmas 2: ovules 2 in each cavity : staminate flowers in ament-like spikes. 1. GARRYA. 
Stigma 1: ovule 1 in each cavity : staminate flowers capitate. 2, Nyssa. 
Flowers perfect: stigmas terminal. 
Flowers in open cymes, not subtended by an involucre: fruit surmounted by the s ie! 
Style. > 
Flowers in a head subtended by a large involucre : fruit surmounted by the calyx. 4. CYNOXYLON.' 
1. GARRYA Dougl. 
Shrubs, with 4-angled branches. Leaves opposite, persistent : blades entire or slightly 
toothed. Flowers dioecious, inconspicuous, in axillary ament-like spikes, the staminate 
with 4 narrow sepals, no petals, 4 stamens with distinct filaments and linear anthers, and an 
obsolete gynoecium.  Pistillate flowers with 2 more or less manifest sepals and a gynoe- 
cium with a 1-celled ovary, 2 stigmas and 2 pendulous ovules. Drupe short, terminating 
1n the 2 persistent stigmas. Seeds 2, or sometimes 1, flattened. 
! The genera Svida and Cynozylon are commonly included in the genus Cornus. 
