89 
Order LXVI. LINACEiE. The Flax Tribe. 
Line^, DC. Theorie, ed. 1. 217. (1819) ; Prodr. 1. 423. (1824) ; Lindl. Synops. 53. (1829). 
Essential Character. — Sepals 3-4-5, with an imbricated aestivation, continuous with 
the peduncle, persistent. Petals equal in number to the sepals, hypogynous, unguiculate, 
with a twisted aestivation. Stamens equal in number to the petals, and alternate with 
them, united at the base in a hypogynous ring, from which proceed little teeth opposite to 
the petals, and indicating abortive stamens ; anthers ovate, innate. Ovary with about as 
many cells as sepals, seldom fewer; styles equal in number to the cells; stigmas capitate. 
Capsule generally pointed with the indurated base of the styles, many-celled; each cell 
partially divided in two by an imperfect spurious dissepiment, and dehiscing with two 
valves at the apex. Seeds in each cell single, compressed, inverted ; albumen usually present; 
embryo straight, fleshy, with the radicle pointing towards the hilum ; cotyledons flat. — 
Herbaceous plants, or small shrubs. Leaves entire, without stipules, usually alternate. 
Petals fugitive. 
Affinities. It is remarked by De Candolle, that this order is intermediate, 
as it were, between Silenacese, Malvaceae, and Geraniacese, from all which, 
however, it is obviously distinguished. Aug. de St. Hilaire considers it a mere 
section of Geraniacese. But the want of a gynobasic structure, the strongly 
imbricated calyx, and the regular flowers, together with the constant presence 
of a small quantity of albumen in the seeds, rather point out its affinity with 
the Cistal alliance, and especially with Elatinacese, of which it is a sort of de- 
candrous exstipulate form. 
Geography. Europe and the north of Africa are the principal stations of 
this order, which is, however, scattered more or less over most parts of the 
globe. Several are natives of North and South America, 2 only are found in 
India, 1 in New Zealand, and none in New Holland ; for the L. angustifolium 
mentioned by De Candolle as having been sent him from that country, had 
probably, as he suggests, been introduced from Europe. It is stated by Ri- 
chardson, that the most northern limit of this order in North America is 54® 
N. Ed. P. J. 12. 209. 
Properties. The tenacity of their fibre, and the mucilage of their 
diuretic seeds, are striking characters of Linacese, which are also usually re- 
markable for the beauty of their flowers. The leaves of L. catharticum 
are purgative. Linum selaginoides is considered in Peru bitter and aperient. 
DC. 
GENERA. 
Linum, L. 
Reinwardtia, Dumort. 
Radiola, Gmel. 
Order LXVIL HUGONIACE.E. 
HuGONiACEiE, Arnott Prodr. FI. Ind.Penins. 1.71. (1834). 
Essential Character. — Calyx without an involucre, persistent, 5-sepaled; sepals 
distinct, acute, unequal ; the two exterior lanceolate, densely pubescent on the back ; ano- 
ther dimidiate-ovate, the straight side pubescent, the rounded side testaceous and shining ; 
the two inner ones roundish ovate and suddenly pointed, testaceous, and shining except 
the short pubescent point: aestivation imbricated, quincuncial. Petals hypogynous, 5, 
alternate with the sepals, shortly unguiculate : aestivation twisted. Stamens hypogynous, 
10, afl fertile; filaments wmtQd. at the base into an urceolus, free and filiform above ; anthers 
cordate-ovate, erect, 2-celled, opening by two longitudinal clefts. Torus slightly elevated, 
supporting the staminal urceolus and the ovary. Ovary roundish, coriaceous, glabrous, 
