depa] 



Clje Erea^urj? of 380tanp. 



394 



not separate spontaneously from the 

 spore-cases. 



DEPAUPERATE. When some part is 

 less perfectly developed than is usual in 

 plants of the same family ; thus, when the 

 lower scales of the head of a cyperaceous 

 plant produce no flowers, such scales are 

 said to be depauperated, or starved. 



DEPPEA. The name of a Mexican shrub 

 of the cinchona family, the wood and bark 

 of which are of a red colour. The flowers 

 are yellow arranged in cymes ; the limb of 

 the calyx has four small teeth ; the corolla 

 is wheel-shaped ; the filaments are very 

 short, nevertheless, the anthers project 

 from the corolla ; the fruit is a capsule 

 bursting by two valves. [M. T. M.] 



DERMA. In Greek compounds = the 

 bark or rind. 

 DERMIS. The skin of a plant. 



DESCENDING. Having a direction gra- 

 dually downwards. 



DESERT ROD. Eremostachys. 



DE'SESPOIR DES PEINTRES. (Fr.) 

 Saxifraga umbrosa. 



DESFONTAINE A. The name of a genus 

 of Peruvian shrubs of doubtful affinity, 

 but somewhat allied to Solanacece and 

 GentianacecB. The leaves are thick with 

 spiny margins like those of a holly; the 

 flowers are axillary, stalked, five-parted ; 

 the corolla tubular, more than twice the 

 length of the calyx, the lobes of its limb 

 imbricated before expansion ; stamens 

 five, concealed within and attached to the 

 corolla; anthers opening longitudinally; 

 ovary one-celled with five parietal pla- 

 centas ; style thread-like. The fruit is 

 berry-like with numerous seeds. B. spinosa, 

 with its deep green spiny leaves, and splen- 

 did scarlet flowers, is a most ornamental 

 greenhouse plant. [M. T. M.] 



DESICCATIO. In very hot countries, 

 and in dry seasons in those which have a 

 more temperate climate, not only is the 

 duration of annual plants cut short, but 

 many perennials fall a sacrifice. Trees 

 which send their roots down deeply into 

 the soil may stand the trial better, while 

 those with more superficial roots suffer ; 

 but even in climates like our own, two 

 years of annual drought like 1858 and 1859 

 will cause the death of many a deep-rooting 

 tree, where the vitality was previously 

 low. "Where plants have suffered from 

 want of water, a too liberal supply at 

 once is apt to bring mischief; and in 

 yougn trees which have been long kept out 

 of the ground, the application of damp moss 

 to the bark in a shady place is better than 

 immediate planting. [M. J. B.] 



DESMANTHPS. A genus of tropical 

 and subtropical Indian and American 

 herbs of the leguminous family. The 

 stems seldom exceed three feet in height, 

 and are furnished with twice-pinnate 

 leaves composed of numerous small leaf- 

 lets like those of the sensitive plant ; the 



leaf-stalks are furnished with one or more 

 glands, and at their base are two small 

 setaceous stipules. The small green or 

 white flowers are numerous, and borne in 

 round stalked heads which arise from the 

 axils of the leaves, and consist of a bell- 

 shaped calyx, five petals, and five or ten 

 stamens, though sometimes flowers are 

 found in which there are neither stamens 

 nor pistil. The pods are flat, smooth, 

 membranaceous, several-seeded, and about 

 an inch in length ; when ripe they split 

 into two portions, while in Mimosa, to 

 which this genus is nearly allied, they break 

 up into as many portions as there are 

 seeds. The little brown polished seeds 

 of B. virgatus are in Jamaica strung like 

 beads, and used for making bracelets, 

 work bags, &c. B. brachylobus is a Texan 

 plant, sometimes known as Darlingtmia; 

 but that name is now given to the Califor- 

 nian pitcher plant. [A. A. B.] 



DESMIDIACEiE. A natural order of 

 green-spored A Igce, remarkable for their 

 mode of reproduction, and for the eccen- 

 tric and varied, forms assumed by many 

 of the species. The more typical species 

 of the group, as the name implies, consist 

 of a chain of connected joints, increasing 

 by the continued addition of two new half- 

 joints in the centre, so that the two ex- 

 treme members of the chain are the oldest 

 and the two in the centre the youngest. In 

 the majority of instances, however, the 

 disarticulation takes place on the forma- 

 tion of the first new half-joints, in such a 

 manner that the two new individuals con- 

 sist of half the old plant connected with 

 half of the new, a mode of increase which 

 obtains also in Biatomaccai. Fructification 

 takes place, though rarely, by the conjuga- 

 tion of two individuals by means of lateral 

 tubes or simple contact, as in Conjugate?-, 

 the spore affecting a variety of interesting 

 forms, and being often strongly spinulose, 

 the spines being occasionally complicated 

 in structure. The new individual is pro- 

 duced from this by the formation of a ver- 

 tical partition in the centre, and the sub- 

 sequent formation of two new half-joints, 

 so that the proper form of the species is 

 not attained till the third generation, if so 

 soon. 



Besmidiacece differ from Biatomacece in 

 their green colour, and the absence of 

 silex. The general appearance of the 

 plants, moreover, is totally different. 

 They occur in pools, running streams, &c, 

 and appear to be more frequent in Europe 

 than elsewhere ; though North America 

 produces many species, and Closteria occur 

 in the Himalayan collections. We are not 

 aware that they are ever attached at any 

 period of growth. In one or two instances 

 the endochrome is spiral or not equally 

 diffused. In general the joints are deeply 

 constricted, but this is not always the 

 case, and in Closterium, in which the plant 

 consists of two elongated curved cones 

 applied to each other by thin bases, there 

 is not the slightest constriction. In this 

 genus the joints are often as distinctly 



