# An Illustrated Flora of the Northern United States, Canada and the British Possessions/Salviniaceae

Family 7.   Salviniàceae   Reichenb.   Consp. 30.   1828.
Salvinia Family.
Small floating plants with a more or less elongated and sometimes branching axis bearing apparently 2-ranked leaves. Sporocarps soft, thin-walled, borne 2 or more on a common stalk, 1-celled, with a central often branched receptacle, which bears megasporanges containing a single megaspore or microsporanges containing numerous microspores. The megaspores germinate into prothallia which bear archegones, the microspores into prothallia which bear antherids.
The family consists of two genera.
Salvinia. :
| • | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | Leaves minute, closely imbricated on pinnately branching stems. | 2. | Azolla. |

## 1.0

1.  Salvinia   Adans.   Fam. Pl. 2: 15.   1763.
Floating annual plants with slender stems bearing rather broad 2-ranked leaves, these finely papillose on the upper surface. Sporocarps globose, depressed, 9-14-sulcate, membranous, arranged in clusters, 1 or 2 of each cluster containing 10 or more sessile megasporanges, each containing a single megaspore, the others containing numerous smaller globose pedicelled microsporanges with very numerous microspores. [Name in honor of Antonio Maria Salvini, 1633-1729, Italian scientist.]
About 13 species widely distributed. Only the following, the generic type, in the United States.

### 1.1

* 1.  Salvinia nàtans  (L.) Hoffm. Floating Moss.   Fig. 87.
* Marsilea natans L. Sp. PI. 1099. 1753.
* Salvinia natans Hoffm. Deutschl. Fl. 2: 1795.
* Leaves oblong, rather thick, obtuse or emarginate at the apex, rounded or cordate at the base, entire, spreading, 6'-12' long, pinnately veined, bright green and papillose above, the lower surface densely matted with pellucid brown hairs; spordcarps 4-8 in a cluster, the upper ones containing about 10 megasporanges, each containing a single megaspore, the remainder containing numerous microsporanges each with numerous microspores ; megaspores marked with 3 obtuse lobes, these meeting at the apex.
* Bois Brulé Bottoms, Perry Co., Missouri, and near Minneapolis, Minn. Introduced into ponds on Staten Island, N. Y. Reported by Pursh in 1814 from central
* New York, but his exact station is unknown. Widely distributed in Europe and Asia.

## 2.0

2.  Azólla   Lam.   Encycl. 1: 343.   1783.
Minute moss-like reddish or green floating plants, with pinnately branched stems covered with minute imbricated 2-lobed leaves, and emitting rootlets beneath. Sporocarps of two kinds borne in the axils of the leaves, the smaller ovoid or acorn-shaped, containing a single megaspore at the base and a few corpuscles above it whose character is not fully known, the larger globose, producing many pedicelled sporanges, each containing several masses of microspores which are often beset with a series of anchor-like processes of unknown function. [Greek, signifying killed by drought.]
About 5 species of wide geographic distribution. Type species : Azolla filiculoides Lam.

### 2.1

* 1.  Azolla caroliniàna  Willd. Azolla.   Fig. 88.
* Azolla caroliniana Willd. Sp. Pl. 5: 541. 1810.
* Plants greenish or reddish, deltoid or triangularovate in outline, pinnately branching, sometimes covering large surfaces of water. Leaves with
* ovate lobes, their color varying somewhat with the amount of direct sunlight, the lower usually reddish, the upper green with a reddish border. Megaspores minutely granulate, with three accessory corpuscles; masses of microspores armed with rigid septate processes.
* Floating on still water, Ontario and Massachusetts to British Columbia, south to Florida, Arizona and Mexico. Also in tropical America. Naturalized in lakes on Staten Island, N. Y.