96 | SALVINTIACEAE. | Azolla. 
Family If. SALVINIACEAE. 
Fugacious annuals, of small size, floating in quiet waters. Stems 
simple or branched. Leaves small, often minute, apparently distichous, 
sessile or shortly petiolate, simple or lobed. Sporocarps or conceptacles 
on the under-surface of the stem, either clustered on the divisions of an 
altered submerged leaf, or in pairs in the axils of the leaves, globose or 
ovoid, membranous, indehiscent, of two kinds, both borne on the same 
plant ; one kind containing a single or many macrosporangia, the other 
enclosing numerous microsporangia. Macrosporangia containing a single 
macrospore ; microsporangia with numerous microspores. 
Genera 2; species about 18, mainly tropieal or subtropical. In germination the 
macrospore produces a rather large prothallium, which remains attached to it, and 
which bears one or more archegonia. The microspores each develop a rudimentary 
prothallium bearing a single antheridium containing spermatozoids, fertilization taking 
place in the same way as in ferns. In the genus Salvinia, which is not found in New 
Zealand, the antheridia are formed while the microspores are contained within the 
microsporangium ; but in Azolia the microspores escape in groups called massulae, 
each with its proper membrane, and the antheridia are developed within the massulae. 
1. AZOLLA Linn. 
Floating water-plants. Stems copiously pinnately branched, emitting 
on the under-side numerous rootlets. Leaves densely imbricating, very 
minute, sessile, deeply and unequally 2-lobed. Sporocarps or concept- 
acles in pairs in the axils of the leaves on the under-surface of the stem, of 
two kinds: one kind larger, globose, enclosing numerous microsporangia, 
each of which contains numerous microspores arranged in separate groups 
or massulae furnished with a membranous envelope; the other smaller, 
ovoid, containing a single macrosporangium within which is a solitary 
macrospore. Macrospores each crowned with few or many swimming- 
floats ; massulae of the microspores armed with simple or hooked bristles. 
A small genus of :. or 5 species, found in most tropical or warm temperate regions. 
1. A. rubra R. B. Prodr. (1810) 167.—Floating, red or reddish-green, 
often gregarious and covering large sheets of water; the separate plants 
4—| in. long, orbicular or ovate or somewhat deltoid, copiously bipinnate. 
Leaves densely imbricating, about 4, in. long, 2- lobed, the lobes ovate, 
obtuse. Larger sporocarps globose, about 3'5 in. diam. ; the massulae of 
the microspores armed with copious hooked bristles. Smaller sporocarps 
hardly more than half the size, oblong; the solitary macrospore crowned 
with 3 swimming-floats.— Hook. f. Fl Nov. Zel. ii (1855) 56; Handb. 
N.Z. Fl. (1864) 392; Benth. Fl. Austral. vii (1878) 680; Bak. Fern Allies 
(1887) 137; Cheesem. Man. N.Z. Fl. (1906) 1031. 
NortH AND SourH Isnanps, Stewart IsuAnp : Abundant in still waters throughout. 
Also found in Australia and Tasmania, and very closely allied to the South 
American A. filiculoides Lam., of which some authors consider it to be a variety. 
. 
. Family IV. LYCOPODIACEAE. 
Perennials, from a few inches to a few feet high. Stems erect or 
pendulous, or prostrate or creeping, simple or more usually dichotomously 
branched, often hard and wiry, usually leafy throughout. Leaves small, 
simple, entire or serrulate, more or less decurrent at the base, indistinctly 
