Under the name of _Spiderwort_, the old Botanists arranged many plants of very different genera: the name is said to have arisen from the supposed efficacy of some of these plants, in curing the bite of a kind of spider, called _Phalangium_; not the _Phalangium_ of LINNAEUS, which is known to be perfectly harmless: under this name, PARKINSON minutely describes it; he mentions also, how he first obtained it. "This Spiderwort," says our venerable author, "is of late knowledge, and for it the Christian world is indebted unto that painful, industrious searcher, John Tradescant, who first received it of a friend that brought it out of Virginia, and hath imparted hereof, as of many other things, both to me and others." TOURNEFORT afterwards gave it the name of _Ephemerum_, expressive of the short duration of its flowers, which LINNAEUS changed to _Tradescantia_. Though a native of Virginia, it bears the severity of our climate uninjured, and being a beautiful, as well as hardy perennial, is found in almost every garden. Though each blossom lasts but a day, it has such a profusion in store, that it is seldom found without flowers through the whole of the summer. There are two varieties of it, the one with white the other with pale purple flowers. The most usual way of propagating it is by parting its roots in autumn to obtain varieties, we must sow its seeds. [106] IBERIS UMBELLATA. PURPLE CANDY-TUFT. _Class and Order._ TETRADYNAMIA SILICULOSA. _Generic Character._ _Corolla_ irregularis: _Petalis_ 2 exterioribus majoribus: _Silicula_ polysperma, emarginata. _Specific Character and Synonyms._ IBERIS _umbellata_ herbacea, foliis lanceolatis, acuminatis, inferioribus serratis; superioribus integerrimis. _Linn. Syst. Veg. ed. 14._ _Murr. p. 589. Sp. Pl. p. 906._ THLASPI umbellatum creticum, iberidis folio. _Bauh. Pin. 106._ DRABA S. Arabis S. Thlaspi Candiae. _Dod. pempt. 713._ THLASPI creticum umbellatum flore albo et purpureo. Candy-Tufts, white and purple. _Park. Parad. p. 390._ [Illustration: No 106] The Candy-Tuft is one of those annuals which contribute generally to enliven the borders of the flower-garden: its usual colour is a pale purple, there is also a white variety of it, and another with deep but very bright purple flowers, the most desirable of the three, but where a garden is large enough to admit of it, all the varieties may be sown. For want of due discrimination, as MILLER has before observed, Nurserymen are apt to collect and mix with this species the seeds of another, viz. the _amara_, and which persons not much skilled in plants consider as the white variety; but a slight attention will discover it to be a very different plant, having smaller and longer heads, differing also in the shape of its leaves and seed vessels, too trifling a plant indeed to appear in the flower-garden.