VioLALEs.] CRASSULACEiE. 345 



Are not these bodies analogous to the scales out of which the stamens of Beancapers 

 spring ? If so, an unsuspected affinity exists between these Orders. To me it appeal's 

 that if we were to resolve the fruit of a Sauvagesia, or any other of this Violal Alliance, 

 into its component parts, the resvUt would be wliat we find in Sedum and Crabsula. 

 EndUcher entertains a similar opinion, considering the Houseleeks certainly allied to 

 Turnerads, De Candolle observes (Memoirc, p. 5.) that there is no instance of a double 

 flower in the Order, although it might have been expected from then* analogy m struc- 

 tm'e with Cloveworts. Semper\'ivimi tectorum exhibits almost constantly the singular 

 phenomenon of anthers bearing o\Tiles instead of pollen. Adolphe Brongniart has 

 remarked that m certain Houseleeks no medullary rays are to be found. He describes 

 the woody cyhnder of Sempervi^alm as consisting of little parcels of annular and spiral 

 vessels immediately around the pith, on the outside of which are placed fusiform woody 

 fibres with very fine 4-sided dots, aiTanged in radiating rows, and intermingled with 

 some parcels of annular and reticulated vessels. These fibres are all in contact, are 

 entirely destitute of medullary processes, and are only interrupted in order to leave a 

 passage for the vascular bundles belonging to the leaves, and for the cellular tissue that 

 accompanies them. j\I. Brongniart states, however, that this structm-e is not of constant 

 occm'rence in the Order of Houseleeks. On the contrary, he describes the Crassula 

 poi'tulacacea m the following words : " In this plant it may be said, notwithstanding the 

 large size at which it aiTives in a few years, that there is no woody zone at all ; in it, 

 that very hard tissue, which is fovmd in regular concenti'ic circles in other Houseleeks, 

 and which consists of dotted woody fibre and vessels, is entirely wanting ; the stem in 

 fact contains nothing more than bundles of the medullary sheath, composed entu'ely of 

 spu'al vessels, false tracheae, with annular and reticulated vessels ; but these bundles 

 increase and multiply, so that they may be from 40 to 50 in an old stem, wliile there is 

 not more than 20 or 24 in a young branch. They then are 2 or 3 milHmetres thick, in 

 the du'ection of the rays, instead of half a millimetre. Finally, the celhdar space which 

 they smTound, or the pith, itself augments from 4 or 5 millimetres to 3 or 4 centimetres. 

 So that every part continues to grow, whether cellular or vascular ; but the bmidles of 

 the medullary sheath, thus increased in number and size, still remain entirely composed 

 of annular vessels or false spirals, without intermixture of woody fibre, and are sepa- 

 rated by hard medullary processes. Thus we have in this Order an example of essen- 

 tial differences in the anatomical structure of the trunk." — Obs. on Sir/illaria, Arch. 

 Mus. 1. 437. Schleiden found in an old stem of an Echeveria an entire uniform mass 

 of wood, formed of parench}Tna without vessels, and scattered therein were vertical 

 cords of very thin-sided parenchjina, in the midst of which ran spiral vessels, most 

 of which might still be vmrolled {Wiegman, 1839); and he suspects that it may belong 

 to the whole of this Natm-al Order. I do not, however, find it in Echeveria Imida, whose 

 succulent stem has a very large pith, and a ring of extremely imperfect wood, among 

 which spii'al vessels are distributed with gi'eat irregularity. 



It appears, from De CandoUe's researches, that of the 272 species of which he supposed 

 the Order to consist, 133 are found at the Cape of Good Hope, 2 in South America 

 beyond the tropics, 2 in the same comitiy within the tropics, none m the West Indies 

 or the Mamitian Islands, 8 in ^Mexico, 7 in the United States, 12 in Siberia, 18 m the 

 Levant, 52 in Europe, 1 8 in the Canaries, 1 in Southern Africa beyond the limits of the 

 Cape, 9 in Barbary, 3 in the East Indies, 4 in China and Japan, and 2 in New Holland. 

 To these are to be added several species from the Himalayas. They are found in the 

 driest situations, where not a blade of gi'ass nor a particle of moss can grow, on naked 

 rocks, old walls, sandy hot plains, alternately exposed to the heaviest dews of night and 

 the fiercest rays of the noon-day sun. Soil is to them a somethmg to keep them station- 

 ary, rather than a source of nutriment, which in these plants is conveyed by myriads of 

 mouths, invisible to the naked eye, but covering all theu' surface, to the juicy beds of 

 cellular tissue w hich lie beneath them . 



Refrigerant and abstergent properties, mixed sometimes with a good deal of acridity, 

 distinguish them. The fishermen of Madeii'a inib their nets with the fresh leaves of the 

 Ensiao or Sempervivum glutinosum, by which the nets are rendered as dm-able as if 

 tanned, provided they are steeped m some alkaline liquor. Malic acid exists in Semper- 

 vivum tectorum combined with lime. Kalanchoe brasihensis appears to fonn an excep- 

 tion to the general acrid and stimulating properties of the Order. The Brazilians use 

 it as a refrigerant ; and this is the common quahty of the Order. Sedum oclu'oleucum, 

 the a^Cuiou TO jxiKpov of Dioscorides, and Sempervivum tectoiiira are notable instances ; 

 Sedum Telephium is another, and also astrmgent : its leaves boiled in milk are used by 

 country people m diarrhoea. Its acridity on the other hand gave its name to Sedum 

 acre, a rubefacient emetic and purgative, Bryophyllum calycmimi is considered a vul- 



