A SYNOPSIS OF THE PLANT KINGDOM 



9 



Only one genus and a few species of tropical distri- 

 bution are known, the only aquatic species among the 

 true ferns. The habit, the absence of son, the variable 

 annulus, and the sunken antheridia are distinctive. 



This fern is sometimes cooked and eaten as greens. 



One or two species are frequently grown for aquaria 

 and aquatic gardens. 



7. Schizaeaceae (from the genus Schizxa, cleft, alluding 

 to the leaves). CURLY-GRASS FAMILY. Fig. 3. Ferns 

 of very diverse habit, some extremely small, others 

 climbing: stem mostly oblique or horizontal: leaves 

 very diverse, usually pinnate or palmate; veins forking: 

 sporangia thin-waUed, usually scattered, at first mar- 

 ginal, later sometimes exceeded by the margin of the 

 frond, often appearing spiked or panicled, sessile; no 

 apparent indusium; annulus transverse, apical, com- 

 plete; dehiscence vertical; fertile portion of the frond 

 usually much modified: prothallium of all genera ex- 

 cept Schizaea ordinary; that of the latter genus fila- 

 mentous and extremely branched, resembling that of 

 the filmy ferns. 



In this family are 4 genera and about 70 species, 

 mostly tropical, rare in the colder regions. Two species 

 reach the eastern United States, one of which extends 

 to Newfoundland. The solitary sporangia and trans- 

 verse apical annulus are important characteristics. 



The curly grass (Schizxa pusilla) inhabits bogs, 

 where it may form extended mats of dry, woolly 

 "grass" 1-3 inches high. The sterile leaves are without 

 lauiiiur. Lygodium palmatum is the "climbing fern" 

 of eastern America. The leaf, not the stem, of this 

 plant has unlimited growth, and twines. 



Four genera are in the American trade: Anemia 

 Lygodium, Mohria, and Schiza?a. 



8. Gleicheniaceae (from the genus Gleichenia, named 

 in honor of W. F. Von Gleichen, 1717-1783). GLEICH- 

 ENIA FAMILY. Fig. 2. Terrestrial ferns with peculiar 

 foliage: leaves several times forking owing to the 

 arrested growth of the main divisions which develop in 

 succeeding seasons, only the ultimate branches pinnate 

 (except in one genus): indusium none: sporangia in sori 

 on the under side of the leaf, thin-walled, sessile, pear- 

 shaped; annulus complete, running obliquely around 

 the back and over the top; line of dehiscence extending 

 vertically down the ventral side from a constricted 

 apical place in the annulus: prothallium ordinary, green. 



Two genera and about 26 species occur in tropical lands 

 and the south temperate zone. The family is related 

 to the Schizaeacese but the habit is very different. The 

 peculiar forking of the leaves, as well as the unusual 

 annulus and peculiar dehiscence, are characteristic. 



A few species of Gleichenia are in cultivation in 

 North America. 



9. Osmundaceae (from the genus Osmunda, derived 

 from Osmunder, the Saxon name of the god Thor). 

 OSMUNDA FAMILY. Fig. 3. Ferns of ordinary habit, 

 rarely aborescent: rhizome mostly vertical, thick: leaves 

 large, circinate, 1-3-pinnate, rarely thin and stomate- 

 Irss; petiole somewhat sheathing at the base; fibro- 

 vascular bundle 1; veins forking: indusia wanting: 

 sporangia scattered on the under side of the ordinary 

 leaf, or on the margin or on both sides of modified 

 fertile portions of the leaf, thin-walled, short-stout- 

 pedicelled, globular; annulus imperfect, consisting of a 

 group of cells on one side; line of dehiscence vertical, 

 extending from this group up over the summit: prothal- 

 lium ordinary, green. 



There are 3 genera and 10 or 12 species of general 

 distribution, and others in the Australian region. Three 

 species occur in the eastern United States. The family 

 is related to the Gleicheniacese and Schizaeaceae. The 

 peculiar dehiscence, and the scattered sporangia with 

 the annulus consisting of a group of cells, instead of a 

 ring, are distinctive. 



The family has practically no economic importance, 

 except as ornamental plants, except that the root 



masses are used as matrix on which to grow orchids 

 and other epiphytic plants (see Osmundine). Some 

 have been used in medicine, although their virtues are 

 questionable. The family contains some of our most 

 stately native ferns. 



All three genera are in American horticulture: 

 Leptopteris (leaves thin and no stomates); Osmunda 

 (Royal Fern, Cinnamon Fern), Todea (Grape Fern). 



Order 4. HYDROPTERIDALES 



10. Marsileaceae (from the genus Marsilea, in honor 

 of Giavanni Marsigli, or Aloysius Marsili, Italian.naturul- 

 ists.) MARSILEA FAMILY. Fig. 3. Perennial marsh or 

 aquatic plants with filiform and creeping rhizomes: 

 leaves all from rootstocks, cireinate; rachis without 

 blade or with four leaflets borne together at the apex; 

 leaflets, when present, fan-shaped, rounded at apex; 

 veins dichotomous: sporangia of two sorts, macro- 

 sporangia bearing macro-spores which give rise to egg- 

 cells, and microsporangia bearing microspores which 

 give rise to sperm-cells, both borne together in tiny 

 chambers (sori) in globular capsule-like conceptaclea 

 (sporocarps) which arise from the rootstock or lower 

 portion of the leaf, and are either stalked- or sessile: 



3. Srit!7..K\cF..F.: 1. Aneimia, sporangium. OBMUNUACE.E: 2. 

 Osmunda, sporangium; a, front view; 6, back view. SALVINIACE.E: 

 3. Salvinia, a, whole plant; b, section of sporocarps showing 

 sporangia. MARSILEACE*: 4. Marsilea, a, whole plant; 6, sporo- 

 carp germinating; c, sporocarp emitting gelatinous thread with 

 son. 5. Pilularia, a, cross-section of sporocarp; b, sporocarp 

 emitting sporangia. 



male and female prothallia very much reduced, remain- 

 ing inclosed within the spore-wall, which in the case of 

 the macrospores early becomes ruptured on one side to 

 expose the archegonia. 



Two genera (Marsilea and Pilularia) and about 60 

 species occur, of which 52 or 54 belong to Marsilea. 

 The distribution is general, though mainly tropical. 

 Marsilea is represented in the United States by one 

 native and one introduced species. The family is closely 

 related to the Salviniacese, but the peculiar habit and 

 unusual sporocarps are distinctive. 



