Tuthos,] AEOIDE/E. 845 



and exceedingly variable both in the absolute and relative size and breadth of the petiole and 

 lamina. The common Hongkong variety is precisely the CJiinese one figured in the plate 

 above quoted, 



7. ACORUS, Linn. 



Flowers hermaphrodite, in a cylindrical spike, the spatha linear and continu- 

 ous with the scape. Perianth of 6 concave scales or segments. Stamens 6, 

 opposite the segments. !Pilaments linear, flat. Anthers tei-minal. Ovary 3- 

 celled, with several ovules in each cell. Stigma sessile on the obtuse top. 

 Seeds albuminous. 



A genus probably limited to the following species, and to one other clgsely allied but 

 much smaller one, a native of China and Japan, but not found in Hongkong. 



1. A. Calamus, lAnn. ; Kunth, Unum.ui. 87. A highly aromatic reed- 

 like perennial, with a thick shortly creeping rhizome. Leaves linear, erect, in 

 some specimens only 1 ft., in others 3 to 3 ft. long, and from i^ to ^^ in. 

 broad. Scape as variable in length, the linear leaf-like spatha sometimes 

 scarcely exceeding the spike, in other specimens a foot long or more. Spike 

 1|- to 8 in. long, of a yellowish gTeen.^ — A. Calamus, and probably the 6 

 following species in Schott, Prod. Aroid. 578. 



Common in watercourses at Little Honglcong, Ih/re ; in a ravine of Mount Victoria, Wil- 

 ford ; also Wright and Ranee, both the large and the small states. Jixtends over Europe, 

 central and temperate Asia, and N. America. Frequent in gardens in India, and wild in the 

 northern mountainous districts. 



Okdee CVII. naiades. 



Mowers usually proceeding from- a small sheathing bract. Perianth none, 

 or of 4 small scale-like segments. Stamens 1, 2, or 4. Ovaries either of 3 

 or 4 distinct carpels, each with a single ovule and a separate stigma, or single, 

 with 1 ovule and 3 to 4 stigmas. Fruit of 1, 3, or 4 seed-like nuts, each 

 with 1 seed, without albumen. — Aquatic floating or submerged herbs. Leaves 

 either sheathing at the base or accompanied by sheathing stipules, alternate or 

 rarely opposite. Flowers axillary, inconspicuous, solitary or spiked. 



An Order not numerous in species, but abundantly diffused over all parts of the world, in 

 shallow seas as well as in fresh-waters. 



T. IfAIAS, Willd. 



Flowers unisexual. Perianth none. Male flowers consisting of a single 

 nearly sessile anther, enclosed in a little tubular membranous bract. Female 

 flowers a single ovary, sessile in the sheathing base of the leaf, with 3 to 4 

 subulate stigmas or style-branches. Fruit a small seed-like nut. Embryo 

 straight. — Submerged plants. Leaves opposite or temate, often crowded in 

 clusters, usually serrulate. Flowers axillary. 



A genus of few species, widely dispersed over the greater pai-t of the globe. 



1. U. minor. All. ; Kunth, Enum. iii. 113. Leaves narrow-linear, usually 

 opposite, -J to 1 in. long, with minute serratures, the sheath short and toothed. 

 Flowers monoecious, solitary, or 3 or 3 together in the same axil,- with 1 or 



