19 
IX. 
XAXTHIUM SPINOSUM, Linne. 
The Batburst-Burr. 
The generic name, if really indicated already by Dioskorides, 
is derived from a yellow pigment of this kind of plants, farther 
from the yellow colour of the spinules. The specific name occurs 
first in Professor R. Morison’s writings (1699). Assumed to be 
a native of South-Western Asia, though also thought to have 
originated in South-Western America. Flowering under ordinary 
circumstances only once from the same root. Up to some feet 
high, but generally more dwarfed. Branches finally almost glab- 
rescent. Leaves on short stalks, never very large, in outline 
often rhomboid -lanceolar, usually three-lobed, otherwise almost 
or quite entire or seldom somewhat pinnatilobed, above dark- 
green and beset with appressed scattered short hairlets, more so 
along the axis and venules, beneath from a thin close vestiture 
greyish or whitish, the lobes acute, the terminal lobe much the 
longest ; primary venules prominent. Spinules arising from near 
the base of the leaves, very conspicuous, acicular, usually ternate, 
but at the base connected, yellow, each representing the primary 
axis and the secondary of an undeveloped leaf. Flower -headlets 
quite small, almost or wholly unisexual; the staminate more 
terminal, globular, single or occasionally some few together, the 
pistillate usually in lower axils, all nearly sessile. Involucre of 
the staminate flowers consisting of very small mostly lanceolar 
puberulous bracts in several rows, almost free from each other ; 
receptacle extremely short (drawn too long in the illustrative 
plate), individual flowers many, partly supported by solitary minute 
bracts ; corolla beset with very short hairlets outside; lobes five, 
very short ; tube almost obverse-conic ; filaments of the stamens 
connate into a cylinder or separating ; anthers disconnected, 
soon seceding, linear, curved-apiculate, finally spreading ; pollen 
pale; style, stigmas and ovulary rudimentary or absent. Pistil- 
late flower-headlet often solitary, soon bent downward, its involucre 
ellipsoid, consisting of two enlarging and bilocular ly concrescent 
bracts, all over beset with numerous small very spreading hooked 
inwardly (not outwardly as drawn) yellowish or brownish spinules, 
open at the summit, including only two flowers, bearing a short 
close vestiture except at the spinules, at last hardening, often 
terminated by two straight spinules ; corolla none or rudimentary. 
Stamens absent ; style thinly cylindric ; stigmas two, capillulary- 
semicylindric, emerging and finally spreading. Fruits seed-like, 
elongated, concealed, filling the cavities, somewhat compressed, 
one-seeded, dark-coloured outside, glabrous, devoid of any pappus. 
