CYCADACEAE 
349 
Cyamopsis DC. Leguminosae (ill. 6). 3 sp. trop. Afr., As. C. psora * 
loides DC. is largely cultivated in India as fodder (Guar). 
Cyananthus Wall. Campanulaceae (1. 1). 10 sp. Mts. of mid- and E. 
As. Ovary superior. 
Cyanotis D. Don. Commelinaceae. 35 sp. Old World, trop. 
Cyathea Sm. Cyatheaceae. About 60 sp. trop. and subtrop. Tree 
ferns, forming a very characteristic feature in the scenery of various 
regions. C. medullaris Sw. (N. Z.) is well known, also C. dealbata 
Sw. from the same region. Their pulpy pith is eaten by the natives. 
Cyatheaceae. Filicineae Leptosporangiatae (Homosporous). 9 gen. with 
200 sp. chiefly trop. and subtrop. They are mostly tree ferns with 
stout erect stems, covered with adventitious roots and a palm-like 
crown of leaves at the top. These show the circinate vernation, &c., 
very well. The sori are marginal or on the under side of the leaves, 
naked or with a cup-shaped indusium; the sporangia are shortly 
stalked and have a complete excentric annulus. Chief genera: 
Cyathea, Alsophila, Dicksonia, Hemitelia. 
Cyathodes Labill. = Styphelia Sm. 
Cybianthus Mart. Myrsinaceae (n). 30 sp. trop. Am., Philipp. Is. 
Cybistax Mart. Bignoniaceae (11). 3 sp. S. Am. The leaves of C. 
Sprucei K. Sch. are used as a blue dye, by simply boiling them with 
the cloth. 
Cycadaceae. Gymnospermae. 9 genera with about 75 sp. The sur- 
vivors of a group of plants which in past ages figured largely in the 
composition of the flora of the earth. They reached their maximum 
about the end of the Triassic and beginning of the Jurassic period. 
The C. represent the lowest type of living Phanerogams and remind 
us, in their appearance and habit, of the tree-ferns. The stem is 
usually short and stout, only growing to any noteworthy height in 
Cycas itself, and is often tuberously swollen. It has a long primary 
tap root. In some sp. a sort of felt-work of roots is formed at the 
base of the stem, and a number of short lateral branches of these 
stand erect and may emerge from the soil (see Nat. Pfl .) . At the end 
of the stem there is usually a crown of leaves, and its lower portion is 
covered with scales. There are, in all C. except a few sp. of Macro- 
zamia, two sorts of leaves, foliage- and scale-leaves. They are borne 
spirally upon the stem, and alternately with one another, as a rule 
several circles of scales before each circle of foliage leaves, which they 
protect in the bud. The scales are really leaf bases whose blades 
abort. The foliage leaves are very characteristic. They possess 
usually a thickened, woody, more or less sheathing base, which often 
persists after the fall of the rest of the leaf. There is a stout rachis or 
petiole, frequently thorny at the base, the thorns being ‘metamor- 
phosed’ leaflets. Upon its upper side are two grooves, from which 
spring the leaflets, which may or may not be opposite to one another ; 
there is usually no terminal leaflet. The leaflets may be entire or 
