XYRIDACEJE. 
325 
or unguiculate. Fertile stamens 3, alternating with 3 staminodes ; 
anthers 2-celled, extrorse. Ovary free, sessile, 1-3-celled ; ovules 
numerous, orthotropous • style trifid at the top. Capsule loculicidally 
3-valved. Seeds with a minute embryo placed opposite the hilum, 
outside the albumen. — Perennial acaulescent herbs, with narrow dry 
leaves, the flowers in heads, in the axils of dry hard bracts. Distrib. 
Tropics of both hemispheres. Species 50-60. 
1. XYRIS, Linn. 
Corolla trifid, with oblong unguiculate segments. Stamens 3, short, 
hypogynous, alternating with 3 penicillate staminodia. Ovary usually 
1-celled ; placentas parietal or basal. Capsule 3-valved. Seeds very 
numerous, minute. — Habit as in the order. Distrib. Tropics of both 
hemispheres. Species 50. 
Dwarf, with narrow linear leaves 1. X. humilis. 
Tall, with broad linear leaves 2. X. platycaulis. 
1. X. humilis, Kunth, Enum. iv. 15, Leaves striate, glabrous, 
narrow linear, 1^-3 in. long. Scape 2-5 in., filiform, rigid, rather 
compressed. Heads ± in. long, turbinate, containing about 3 flowers ; 
bracts roundish, coriaceous, emarginate, keeled upwards, brown on the 
back, the sides paler. Sepals narrow, keeled, acute, glabrous. Cap- 
sule oblong, brown, membranous, rather shorter than the bracts. 
Mauritius. Described by Kunth from a specimen in Willdenow’s herbarium. 
Also Madagascar. 
2. X. platycaulis^ Poir. ; Kunth , Enum. iv. 18. Acaulescent, 
densely tufted. Leaves linear, rigid, sheathing the scape at the base, 
4-8 in. long, i- i in. broad. Scape a foot or more long, clasped by a 
leaf for some distance above the base, acutely angled at the top. 
Head globose, \ in. broad ; bracts hard, shining, deltoid, greenish- 
white when young, dark brown when mature. Calyx j- in. long ; sepals 
acutely keeled. Petals nearly twice as long as the calyx. Capsule 
obovoid, brown, retuse, i n * l° n g* 
Mauritius, Petit Thouars in Herb. Willdenow, No. 1070. Also Madagascar and 
Zanguebar. 
Order XCIL* BR0MELIACEJE. 
* Ananassa sativa, Lindl. in Bot. Reg. sub. t. 1068 (Bromelia 
Ananas, Linn. ; Bot. Mag. tab. 1554), the Pine- Apple, a native of Tro- 
pical America, is now established in Mauritius, Seychelles, and 
Rodriguez. It has a fibrous root, a dense sessile rosette of lanceolate 
coriaceous channelled leaves 2-3 feet long with prickly edges, flowers 
in a dense peduncled oblong head with a crown of empty bracts at the 
top, an inferior ovary united to its bract, sepals 3 horny deltoid, 
