Xdnthium.~\ xlvi. composite : cory'MBiferaj. 
251 
5. A. *tomentusa L. (woolly yellow M. or I r .) ; leaves woollv 
pinnatifid, lobes crowded 2 — 3-cleft, segments linear acute, 
corymbs repeatedly compound, scales of the involucre woolly. 
E.B. t. 2532. 
Dry hilly pastures, in Scotland. Spittle-hill, north-west of Balvie, 
Dumbartonshire: and near Paisley. Auehlunkart, Banffshire: P. 
Stewart, Esq. Near Newcastle, Co. Down, Ireland : Miss Keown 
It. 8. — Stem a span or rather more in height. Readily recognised 
by its small size, downy leaves, and much branched corymbs of yellow 
flowers. Formerly much cultivated as a medicinal plant, as well as 
for its beauty. 
Anomalous Genus. 
47. Xanthium 1 Linn. Bur-weed. (Tab. V.) 
Monoecious. — Barren fl. Involucre of few scales, with many 
small capitate flowers , upon a common receptacle. Cal. 6. 
Cor. obovate, sessile. Anthers terminating a tube which is in- 
serted at the base of the cor. Germen abortive. — Fertile fl. 
Involucre single, prickly, with two beaks, entirely closing 2 
flowers ; the 2 stigmas only protruded from small apertures 
within the beaks. Cal. 0. Cor. 0. Fruit 1-seeded, included 
in the enlarged and hardened involucre. — Named from ZavBoc, 
yellow or fair ; because an infusion of this plant was sup- 
posed to improve the colour of the hair. 
1. X.* strumdrium L. (broad-leaved B.) ; stem unarmed, leaves 
cordate angulato-dentate with 3 principal nerves at the base, 
fruit downy its beaks straight the prickles hooked. E. B. 
t. 2544. 
Rare, in waste ground in the south of England, and Kerry, Ireland. 
©. 8, 9. — A rank, weed-like plant, remarkable for the curious 
structure of its flowers, and the prickly involucres which surround the 
fertile ones, enlarging and becoming part of the fruit. It is scarcely 
naturalized, and rarely ripens seed in the south of England. 
1 Tab. V. represents, at fig. 1 a flowering specimen of Xanthmm struinarium ; 
the upper clusters or heads consist of barren, the lower of fertile, flowers. 
Fig. 2. Scale of the involucre with a barren flower, exhibiting the corolla and 
the staminal tube with five anthers. 
Fig. 3. Fertile flower; consisting of a prickly monophyllous involucre with 2 
beaks, and the branches of the stvles protruded beyond the beaks. 
Fig. 4. The same cut open to show the two pistils or flowers without calyx or 
corolla. 
Fig. 5. Fruit enveloped by the persistent involucre (natural size). 
Fig. 6. Single fruit. 
Fig. 7. Seed. 
Fig. 8. Embryo. 
Fig. 9. The same, one cotyledon being removed. 
Fig. 10. The same, cut vertically through the two cotyledons. 
