426 



THE DICTIONARY OF GARDENING, 



SESIA. A genus of Moths, generally called " Clear- 

 wings," in reference to the absence of scales from tl 

 greater part of the surface of the wings, which are con- 

 sequently, nearly transparent. This, together with the 

 length and narrowness of the wings, and the form and 

 colouring of the bodies, gives the Moths a striking re- 



Fio. 480. SESIA APIFORMIS. 



semblance to insects of the widely-different groups of 

 Bees, Wasps, and two-winged Flies. 8. apiformis, one of 

 the largest British species, is very like a hornet in general 

 appearance (see Fig. 480), and is known as the Hornet 



FIG. 48L SESIA VESPIFORMIS. 



Clearwing. Others, e.g., 8. vespiformis (see Pig. 481) 

 and S. formicceformis, are much like some of the smaller 

 Hymenoptera ; while others, e.g., the Currant Clearwing 

 (8. tipuliformis) closely resemble slender, two-winged 

 Flies. These resemblances probably afford protection 

 from enemies. The larvae live in the branches, stems, 

 or roots of various plants, boring into the wood or 

 pith. They become pupae in their tunnels. The more 

 hurtful species are the following: Eed-belted Clearwing 

 (S. myopceformis) the larvae feed, often in large numbers, 

 in the wood of Pear-trees ; the moth is black, with a 

 bright red belt round the middle of the abdomen. 



FIG. 482. LARVA OF SESIA TIPULIFORMIS. 



Currant Clearwing (8. tipuliformis) the larvre ' (see 

 Fig. 482) are common in twigs of Currants; the moth 

 is black, with two narrow, yellow lines on the back of 



Sesia continued. 



the thorax, and three narrow, yellow belts round the 

 body, and the wings are yellowish near the tip, with 

 black veins. Red-tipped Clearwing (8. formicceformis) 

 the larvae feed in Willow and Osier twigs ; the moth is 

 black, with a deep red belt round the abdomen, and a 

 broad, red tip to each fore wing. Hornet Clearwing 

 (S. apiformis) the larvae live in wood of Poplars, each 

 feeding for two years; the moth is much like a hornet 

 in size and colour, being marked with brown, orange, 

 tind yellow. Willow Hornet Clearwing (8. bembeciformis) 

 the larvae live in twigs of Willows and Osiers ; the 

 moth is much like the last-named, but the head is brown, 

 not yellow, and there are no yellow spots on the thorax. 



Remedies are very difficult of application, because of 

 the concealed mode of life of the larvae. Of course, the 

 moths ought to be captured, when they can be found, 

 and this is most likely to be accomplished in the early 

 morning, soon after they crawl out of the pupa cases, 

 and while they are resting on the tree or twig. No 

 remedial measures can be taken while the larvae are in 

 the wood; and when holes are visible the moths have 

 escaped. Badly-infested trees should be cut down and 

 burned, to destroy the larvae. If twigs of Currants, 

 Osiers, or other plants liable to attack, suddenly begin 

 to droop, they should bo cut off, and the la'rvaa therein 

 destroyed. 



SESLERIA (named in honour of Leonard Sesler, an 

 Italian ( physician and botanist). ORD. Graminece. A 

 genus comprising eight species of hardy, perennial, tufted 

 grasses, natives of Europe and Western Asia. Spike- 

 lets two to six-flowered ; panicle spike-formed, often 

 short and bluish, or slightly silvery, sometimes elon- 

 gated. Leaves flat or convolute-terete. The genus, 

 which has no horticultural interest, is represented in 

 the British Flora by S. ccerulea, a plant growing from 

 Gin. to 18in. high. 



SESQTJI. A prefix which, used in Latin compounds, 

 signifies one and a-half; e.g., Sesquipedalis, IJft. 



SESSIIiE. Sitting close on the supporting body, 

 without any stalk. 



SESUVIUM (signification of name unknown, probably 

 arbitrary). ORD. Ficoidece. A small genus (about four 

 species) of stove or greenhouse, erect or prostrate, 

 branched, succulent herbs or sub-shrubs, scattered over 

 tropical sea-shores. Flowers often flesh-coloured or purple, 

 axillary, sessile or pedunculate, solitary, clustered, or 

 rarely sub-cymose ; calyx tube turbinate, the five lobes 

 coloured within ; petals absent ; stamens five. Leaves 

 opposite, slightly fleshy, linear or oblong ; stipules none, 

 or sometimes connate with the petiole in a stipulaeform 

 membrane. S. Portulacastrum and 8. repens are both 

 edible as potherbs, but have a rather salt taste. Two 

 species, both greenhouse, decumbent perennials, call for 

 description here. These thrive in any well-drained, sandy 

 soil. Propagated freely by slightly dried cuttings, in- 

 serted in similar soil, under a glass. Water must be 

 sparingly administered. 



S. Portulacastrum (Portulacastrum). Sea Purslane ; Samphire 

 or Seaside Purslane of the West Indies. A. pedicellate ; calyx 

 green outside, reddish within ; stamens twenty-five to thirty. 

 June and July. 1. linear or lanceolate oblong, flat. 1692. 

 (A. B. E. 201, under name of Aizoon canariense.) The variety 

 sessile has sessile flowers. 



S. revolutifolium (revolute-leaved). /. red and white, sessile ; 

 stamens very numerous ; stigmas five or six. July and August. 

 I. ovate-oblong, with revolute margins, rather glaucous, not deep 

 green. Cuba. (B. M. 1701, under name of S. Portulacastrum 

 var.) 



SETA. A bristle or bristle-shaped body; a slender, 

 straight prickle ; a stiff hair. 



SETARJA (from seta, a bristle ; alluding to the 

 involucre of bristles surrounding the spikelets). ORD. 

 Graminece. A genus comprising about ten species of 



