FDCACE2E. 



FUCACE/E. 



FfO 



B. Spikes with fleshy bracts and perianths. 



36. Soroaia. Ex. Ananaaa, Moras. 



C. a. Spikes with woody bracts. 



37. Strobilus. Ex. Betula. 



b. Spikes with woody bracts and perianths. 



38. Strobilus. Ex. Casuarina. 



V. Spurious Fruits (Fructut spurius). 



39. Cynarkodon. Free one-seeded Achjenia, surrounded by a 



fleshy disc. Ex. Rosa. 



40. Pomum. Many-seeded Achamia in one circle, blended with 



the fleshy disc. Ex. Malus. 



41. Balawta. Many-seed Aehaenia in two circles, blended 



with the fleshy disc. Ex. Piuiica. 

 4 2. JJiclaium. Achaenia enclosed in a hardened perianth or 



corolla. Ex. Spinacia, Mirabilis. 



43. Sphalerocarpium. Achrenia inclosed in a drupaceous 

 perianth. Ex. Hippophde. 



FUCACE^E, a natural order of Alyce, or olive-coloured inarticulate 

 S.-a-Weeds, whose spores are contained in spherical centres, immersed 

 in the substance of the frond. The root has almost always a conical 

 disc, rarely branching or creeping. The fronds are of an olive-brown 

 or olive-green colour, becoming darker in drying ; of a tough leathery 

 substance, and fibrous texture, tearing lengthwise with facility ; 

 dichotomous or pinnate; rarely irregularly branched, but very 

 variable in habit. In the simpler kinds (Splancnidium) there is no 

 distinction into parts (as stem, leaves, receptacle), but the fructifica- 

 tion is equally dispersed through all parts of the plant ; in others 

 (DurvMaa, Sarcophycut) there is a stem ending in a phyllo-caulon or 

 leaf-like frond, through which the fructifications are scattered; in 

 others (ffimanthalia) there is a simple frond of small size, and a 

 branching receptacle of fructification resembling a frond ; in others 

 (Fuctu, Cyttoteira) there is a branching or imperfectly leafy frond, 

 some portions of whose branches finally swell and are converted into 

 receptacles of fruit ; and, finally, in the most perfect kinds (Sargassum, 

 M ni-'jinarfa) there is a branching frond, with well-formed mostly 

 distinct and nerved leaves and receptacles, from their origin set 

 apart as organs of fructification (not formed by swellings of the old 

 branches), developed either in the axils or along the edges of the 

 leaves or branches. Air-vessels are present in almost all, either in 

 Mii'Ulery swellings of the stem and branches, as in facia, or as distinct 

 organs, as in ffarytutimi, stalked, and mostly springing from the same 

 part as the fructification. Receptacles of the fruit, mostly more or 

 less distinguishable from the barren portion of the frond, swollen, succu- 

 lent, often filled with slimy mucus, either formed from the metamor- 

 phosed ends of the branches, or evolved from the axils or sides of the 

 branches or leaves. These receptacles are pierced by minute pores, 

 which communicate with small spherical chambers formed by an 

 introflexion of the walls of the receptacle at the points where they 

 occur. The little chambers (called Coneeptacles by some writers, 

 Scaphidia by others) contain sometimes spores, or reproductive bodies, 

 analagous to the seeds of more perfect plants ; sometimes antheridia, 

 supposed to be analagous with stamens ; sometimes both organs in 

 the same chamber. The spores spring from the sides of the chamber. 

 One of the surface-cells being fertilised, gradually enlarges, projects 

 from the wall of the chamber, becomes more or less obovate, and 

 finally is converted into a perispore, or membranous transparent 

 case, in which is contained the spore or spores. These last are 

 formed from the matter contained within the enlarged cell. At first 

 the contents are nearly fluid, of a pale olive colour; gradually they 

 acquire density, become darker, and at length are consolidated into 

 a single sporule, as in Cystoseira, ffalidrys, &c., or formed into two, 

 four, or eight sporules, as in Fucus, Himanlhalia, &c. The antheridia 

 are borne on branching jointed threads, called Parauemata, which 

 rise, like the spores, from the walls of the conceptacle, and com- 

 monly fill the greater part of its cavity. Each antheridium is an 

 oblong cell, forming the terminal articulation of the branches of the 

 paranemata, and is filled with minute orange-coloured bodies called 

 Sporidia (by 3. Agardh), closely resembling the zoospores of the 

 lower Algce, and like the latter endowed with spontaneous move- 

 ments. The motive organs are vibratory hairs, or cilia, with two of 

 which each little body is furnished. 



The Fucacece are easily known from all other Olivaceous Sea- Weeds 

 by,a character at once natural and easily ascertained, namely, the 

 position of their spores within little hollows sunk in the substance of 

 the plant, and communicating with the surface by a pore. The order 

 is represented in most climates, from high northern and southern 

 latitudes to the equator. Very few species vegetate in the polar 

 regions of either hemisphere. In the north the species of Fucus and 

 Himanlhalia alone reach to the Icy Sea ; and in the Antarctic Ocean 

 the order is limited to DurvUlaca, and to Scytothalia Jaquinotii, a fine 

 Al'jci allied to sub-tropical forms. The British species, excluding 

 three doubtful natives, are but fourteen ; yet from the strictly social 

 habits of several of them, they cover more surface of tidal rocks than 

 all the other Alyce put together. It is these plants which impart the 

 deep brown colour to the belts of rocks exposed on the recess of 

 the tide. 



The following is a synopsis of the British g uera of these plants : 



Sargassum. Branches bearing ribbed leaves. Air-vessels simple. 



Halidrys. Frond linear, pinnate, leafless. Air-vessels divided into 

 several cells by transverse partitions, 



Cystoseira. Ryot scutate. Frond much branched, bushy. Recep- 

 tacles cellular. 



Pycnophyc'Jts. Root branching. Frond cylindrical. Receptacles 

 cellular. 



Fucus. Root scutate. Frond dichotomous. Receptacles filled 

 with mucus, traversed by jointed threads. 



Jii/iiant/talia. Root scutate. Frond cup-shaped. Receptacles 

 (frond-like) very long, strap-shaped, dichotomously branched. 



I. SARGASSUM. Frond furnished with distinct, stalked, nerved leaves, 



and simple axillary stalked air-vessels. Receptacles small, linear, 

 tuberculated, mostly in axillary clusters or racemes. Seeds in 

 distinct cells. The generic name is from Sargazo, the Spanish 

 term for masses of sea-weed found floating in the ocean in some 

 latitudes. 



1. S. vulgare; and 



2. S. bacciferum, though both of them have been found cast on 

 our shores, have no just claim to a place in our British Flora, being 

 natives of the tropics, occasionally driven, with other tropical pro- 

 ductions, by the force of the western currents on our Atlantic coasts. 

 The species of this genus are found over a wide extent of ocean, and 

 have been generally called ' Gulf- Weed." They appear like floating 

 meadows in the midst of the ocean, sometimes for miles in extent, 

 and probably support a larger number of livina; creatures than the 

 most productive pasturage iu Great Britain. Myriads of Mollusks, 

 Radiata, Fishes, and Crustacea may be seen playing about in these 

 masses ; and the abundance of Zoophytes which find shelter in such 

 situations can hardly be estimated. The weed is eaten in China. In 

 the East it is used in salads, and forms a pickle. 



II. HAMDBYS has compressed linear fronds, pinnated with disti- 



chous branches. The air-vessels are lanceolate, stalked, divided 

 into several cells by transverse partitions. The receptacles are 

 terminal, stalked, cellular, pierced by numerous pores, which 

 communicate with immersed spherical conceptacles. 

 //. siliqiuaa has linear very narrow branches, compressed linear 



lanceolate air-vessels, slightly constricted at the septa, rnucronate. 



It is found on rocks and stones in the sea, at and below half-tide 



level. 



III. CYSTOSEIRA has a frond furnished with branch-like leaves, 

 becoming more filiform upwards. The air-vessels are simple, 

 arranged within the substance of the branch-like leaves consecu- 

 tively. The receptacles are cylindrical, more or less lanceolate, 

 tuberculated, and terminal. The seeds in distinct cells. The 

 name is derived from two Greek words, signifying a little sac and 

 a chain. 



C. ericoides has a thick woody short stem, cylindrical, and beset 

 with numerous slender filiform branches, variously divided, and 

 densely clothed with small spine-like awl-shaped ramuli (or leaves). 

 It is found on rocks in the sea, and has the property of being iridescent 

 when under water in a growing state. In drying it becomes nearly 

 black, and does not adhere to paper. 



The other British species of this genus are C. gi-anulata, C. 

 frniicidacea,, C. barbata, and C. fibrosa. 



IV. PYCNOPHYCCS has a root composed of branching fibres. The 

 frond is cylindrical and dichotomous. The air-vessels, when 

 present, innate and simple. The receptacles terminal, cellular, 

 pierced by numerous spores, which communicate with immersed 

 spherical conceptacles, containing in the lower part of the recep- 

 tacles parietal simple spores, and in the upper tufted antheridia. 

 The name is from two Greek words, signifying thick sea-weed. 



P. tuberculatus is found in rock-pools, on the recess of the tide, near 

 low-water mark. It is better known by the name of Fucus tubercn- 

 Inlns. It is very different in many respects from Fucus proper. When 

 dry it becomes very brittle and black. 



V. Fucus has a plane compressed, or cylindrical frond, linear, 



dichotomous, coriaceous. The air-vessels, when present, are 

 innate in the frond, simple, and large. The receptacles terminal 

 (except in Fucus nodosus), turgid, containing tubercles imbedded 

 in mucus, and discharging their seeds by conspicuous pores. 

 P. vesicutosus is common on all our sea-shores. It is the Sea- 

 Ware, Bladder-Fucus, Kelp-Ware, Black-Tang of Scotland, and 

 sometimes Lady-Wrack. In Gothland, according to Linnaeus, it is 

 Swine-Tang, because boiling it and mixing it with a little coarse flour 

 they give it to their hogs. In the Hebrides, cheeses are dried without 

 salt, being covered with the ashes of this plant, which abounds with 

 salt. In Scania it is used as thatch and fuel. The root is a hard flat 

 disc. The fronds are from 2 to 3 feet in length. The air-vessels, 

 as large as nuts, are in pairs ; the receptacles, in pairs, and often 

 forked, terminate in branches. There is a variety of this which is 

 often called Fucu.1 Salticus. It is found among grass and moss in 

 marshy ground occasionally overflowed by the tide. Lightfoot men- 

 tions that during the snow-storms in the Highlands, the red deer 

 descend from the wild mountains to feed on this sea-weed. Ho 



