15 



Oje Crcasuri) of 3Botaitg. 



[acko 



different. In Mosses the whole plant is, 

 as to functions, a prothallium ; in ferns, 

 merely the membranous expansion imme- 

 diately produced on the germination of the 

 spores. Further details may be reserved for 

 each successive group. In those species of 

 Fungi, asPuccinia, Podisoma, &c, where a 

 prothallium is produced, it has the nature 

 of a spore, and germinates in the same 

 manner. 



As regards the tissues, it may be observed 

 that the stem of many acrogens contains 

 distinct vascular tissue. In Jungermannice, 

 where such tissue is rare elsewhere, it 

 almost universally accompanies the spores. 

 In Mosses, as in Sphagnum, there are some- 

 times distinct spirals in the cells of the 

 leaves. The vascular tissue in most of the 

 higher cryptogams is scalariform ; but in 

 Isoetes and Equisetum it is annular, with 

 transitions to short spirals, while in Sela- 

 ginella and Lycopodium there is a transition 

 from short spiral and reticulated cells to 

 elongated cells, which may be called spiral 

 vessels. In the stem of Sphagnum there 

 is tissue closely resembling the glandular 

 tissue of conifers. The spiral coats of the 

 spores in Equisetum will be noticed here- 

 after. The impregnating bodies or sper- 

 matozoids have always flagelliform ap- 

 pendages, sometimes much more highly 

 developed than in the spermatozoa of ani- 

 mals. The principal divisions of acrogens 

 are: 



1. Charace^;. Spores solitary. 



2. Ricciace-E. Capsules valveless, with- 



out spiral cells or elaters. 



3. Marchaxtiace^:. Capsules depen- 



dent, containing elaters. 



4. Jungermanniace^e. Capsules erect, 



containing elaters. 



5. Muscr. Capsules mostly valveless, 



without elaters. 



In these five orders the archegones give 

 rise to the capsule. 



6. Filices. Capsules mostly with an 



elastic ring, but sometimes densely 

 crowded and ringless. 



7. OPHioGLOSSACEiE. Capsules ringless, 



bivalvate. 



8. Eqcisetaceje. Capsules dependent. 



Coat of spores spiral. 



9. Marsileaceje. Capsules multilocular. 

 10. Lycopodiace^:. Capsules axillar, uni- 

 locular. 



In these five orders the spores produce a 

 prothallium bearingarchegones which yield 

 new plants and not capsules. For further 

 details see Berkeley's Cryptogaraic Botany, 

 p. 421. [M. J. BJ 



ACROGLOCHIX. A genus containing 

 only a single species, A.chenopodioides, from 

 Nepal. It has been referred by some to 

 Salsolacece, because of the horizontal posi- 

 tion of the seed, as in Chenopodium ; but 

 the dehiscent utricle seems to separate it 

 from the true Salsolacea? and join it to the 

 Amarantfoacece, with which, however, it 

 does not perfectly agree, for in this order 

 the seeds are vertical. It in fact occupies 



a position equally related to both these 

 orders. The flowers are small, sessile, in 

 axillary cymes. The calyx consists of five 

 equal erect sepals. There are two stamens, 

 and a unilocular ovary, with a single ovule. 

 The leaves are alternate, unequally dentate, 

 and strongly reticulated below. [W. C.J 



ACROLASIA. A genus of Chilian Loa- 

 sacecE, allied to Hentzelia, from which it 

 differs in having a definite number of sta- 

 mens (ten), white flowers, and sinuate-pin- 

 natifld leaves, which are opposite below 

 and alternate above. [W. C] 



ACRONIA. A spurious genus of orchids, 

 now reduced to Pleurothallis. The only 

 species was A.phalangifera, which proves to 

 be identical with Pleurothallis Mathewsii. 



ACRONYCHIA. A genus of rue-like 

 plants (liutacea), distinguished by a short 

 four-parted calyx, four petals, eight sta- 

 mens inserted on a disk ; style short ; stigma 

 capitate, four-lobed ; fruit berry-like, four- 

 celled, each cell containing one seed. A. 

 Cunninghami, a.n evergreen shrub, a native 

 of Moreton Bay, is cultivated in this coun- 

 try. The flowers have a perfume like those 

 of the orange, and the leaves abound in 

 resinous or oily fluid of a powerful turpen- 

 tine-like odour. [M.T.M.] 



ACROPERA Loddigesii. A Mexican and 

 Central American genus of orchids, con- 

 sisting of about four species, growing 

 on the bark of trees. They have the habit 

 of Maxillaric:, with fleshy pseudo-bulbs 

 and a drooping radical inflorescence. Their 

 name, which signifies a pouch at the point, 

 was given them in consequence of there 

 being a sac at the end of their labellum. 

 The flowers are of some dull yellowish 

 colour, with very small misshapen petals. 

 The genus is very near Gongora, to which 

 it is reduced by Reichenbach. 



ACROPHORUS. A genus of polypo- 

 diaceous ferns of the group Cy stopfer i due, 

 distinguished by having its globose patches 

 of fructification, situated mostly at the tips, 

 rarely axillary in the forks of the veins, 

 these sori being covered by suborbicular 

 indusia affixed by their posterior side. 

 They form a small genus, serving to unite 

 the BavallicB with the Cystopterideae. The 

 plants have creeping rhizomes, and very 

 elegant membranaceous, pinnate or decom- 

 pound, free-veined fronds, of which the 

 divisions are either equal-sided or dimi- 

 diate. There are about a score of species, 

 including those referred sometimes to 

 Leucostegia and Odontoloma. The larger 

 proportion of these are natives of India 

 and the East. [T. M.J 



ACROPHYLLTJM. A genus of Cuno- 

 niocea?, founded upon a Tasmanian plant 

 allied to Weinmannia, but distinguished 

 by the absence of -a disk in the flowers. 

 A. venosum is a small erect shrub with 

 evergreen leaves placed in whorls of three ; 

 they are nearly sessile, oblong, cordate, 

 acute, serrated, and smooth ; the stipules 

 are small and membranous ; and the flowers 

 are small, white tinged with red, in dense 



