and small flowers in a spirally-twisted 

 spike, by which the genus is easily recog- 

 nised. The name is derived from speira a 

 'spiral' and anthos a 'flower,' in allusion 

 to the spiral arrangement of the flowers. 

 The tuberous roots of S. autumnalis were 

 formerly esteemed as an aphrodisiac. S. 

 diuretiea is administered in Chili in cases 

 of ischurv. Three species are found in 

 the British Isles. [W. B. H.] 



SPIREE. (Fr.) Spircea. 



SPIRES. Phragmites communis; also 

 applied to Rushes and Sedges. 



SPIRIDENS. Agenus of mosses remark- 

 able both as regards size and structure. 

 The peristome is double, the outer com- 

 posed of sixteen long teeth, which when 

 free curl upfrom within into a spiral, while 

 the inner consists of a membrane divided 

 into as many cilia, in part free, in part 

 combined above. The capsule is lateral 

 and uneaual. Though the genus is pleuro- 

 carpous, it has rather the habit of a gigan- 

 tic Burtramia than of a Hypnum. S. 

 Ezimco.rdtii occurs in Java, Tahiti, and the 

 Philippine Isles, attaining a length of 

 more than a foot. It belongs to a small 

 natural order, Cryptothecei, distinguished 

 by the cylindrical stem, imbricated leaves, 

 and mitriform veil. The order is repre- 

 sented in this country by Crypticea hetero- 

 malla, which is common on trees, and by 

 the rare Baltonia splachnoides, which has 

 not been found out of Ireland. A species 

 of Bendropogon, which belongs to the 

 same order, hangs down in great masses 

 from trees in Mexico, and is an admirable 

 substance for packing. [M. J. B.J 



SPIRIT-LEAF, or SPIRIT-WEED. 

 Ruellia tuberosa, now called Cryphiacan- 

 thus barbadensis. 



SPIROCH.ETA. A genus of Composites, 

 comprising an annual herb of Columbia. 

 The stem is decumbent; the involucre is 

 of two rows of bracts; the flowers equal, 

 each with a slender tube, dilated above 

 into a five-cleft throat; and the style di- 

 vided into two linear awl-shaped branches. 

 Fruits multicostate, oblong, covered with 

 glandular hairs; pappus in one row, con- 

 sisting of four smooth hairs twisted 

 spirally at the points, whence the name of 

 the genus. [M. T. MJ 



SPIRODELA differs from Lemna in the 

 presence of spiral vessels in all its parts, 

 as well as in some points of less cardinal 

 importance. The genus is represented in 

 this country by the Greater Duckweed, & 

 polyrhiza, the largest of our British 

 species. Its fronds are roundish fleshy, 

 nearly half an inch in length, green above, 

 purple below, the roots numerous and clus- 

 tered. The flowers are very rarely observed, 

 and the f rui t is unknown. [M. T. MJ 



SPIROEOBE^E. One of the divisions of 

 the Cruciferce, distinguished by having 

 the cotyledons incumbent and spirally 

 twisted. 



SPIRONEMA. A genus of Commelyna- 



cece, established by Lindley for a Mexican 

 plant, more curious than handsome, with 

 large oblong-lanceolate acute radical leaves, 

 and erect leafless almost rush-like flower- 

 ing stems, havingthe small fragrant flowers 

 clustered along its rigid branches, in the 

 axils of chaffy scales. The three rigid sepals 

 and three extremely delicate petals are the 

 same as in many other Commelynacece, but 

 the structure of the stamens is peculiar : 

 the very slender filaments contain spirally- 

 twisted bundles of vessels, and the anthers 

 are placed transversely at the base of a 

 large delicate heart-shaped connective. 



SPIROSTACHYS. A South African tree 

 constituting a genus of Euphorbiacece. 

 The leaves are entire stalked smooth ; the 

 flowers monoecious ; the males in crowded 

 catkins, with spirally arranged bracts, 

 their calyx enclosed within the bract; 

 and the females solitary at the base of the 

 male catkin, or in pairs, with a three- 

 celled ovary, and thick style supporting 

 three thick recurved stigmas. The generic 

 name is given in allusion to the spirally 

 arranged bracts of the catkin. [M. T. MJ 



SPITHAMA (adj. SPITHAM.EUS). Se- 

 ven inches, or the space between the 

 tip of the thumb and the forefinger sepa- 

 rated as widely as possible. 



SPIXIA. A genus of Brazilian trees of 

 the family Euphorbiacece. The leaves are 

 large and leathery ; the flowers are axillary 

 dioecious, surrounded by an involucre of 

 somewhat globular form, studded by star- 

 shaped hairs; the calyx, is small, two to 

 three-parted ; stamens two to three, longer 

 than the calyx, surrounding four rudi- 

 mentary ovaries. In the female flowers 

 there is a two-leaved calyx surrounding an 

 oblong hairy three-celled ovary; stigma 

 entire ; fruit capsular. [M. T. MJ 



SPLACHNEI. A natural order of acro- 

 carpous mosses, characterised by a straight 

 ' capsule with a well-marked and often large 

 : swelling (apophysis) at the base, diapha- 

 I nous large-celled leaves, the spores radi- 

 ating in lines from the columella, and the 

 ! plants growing on decayed wood or the 

 ' dung of animals. They are amongst the 

 mostremarkable of mosses, especially those 

 which occur in the Northern Hemisphere. 

 The peristome is generally well-marked, 

 and in Tayloria splachnoides the teeth are 

 remarkably long, and singularly curled af- 

 ter the lid has fallen. In (Edipodium, how- 

 ever, there is no peristome. It is singular 

 that the species of the Northern Hemi- 

 sphere grow on dung, while those of the 

 Southern Hemisphere (with one exception) 

 only occur on decayed wood. [M. J. BJ 



SPLACHNUM. A beautiful genus of 

 mosses remarkable for the immense de- 

 velopment of the apophysis in several 

 species, which gives them a very striking 

 appearance. In S. rubrum and luteum (the 

 former of which is European, and the lat- 

 ter extends to America) it is shaped like an 

 umbrella, and is of a red or yellowish hue; 

 while in S. vasculorum. which occurs in the 



