HYDROCLEYS 
428 
(=H. Commersonii Y\ch. = Limnoc kar is Humboldti Rich.), often 
cultivated; it is a water plant with a striking resemblance in habit to 
Nymphaea or Limnanthemum. 
Hydrocotyle (Toum.) Linn. Umbelliferae (1). 70 sp. trop. and temp. 
1 in Brit., H. vulgaris L., the white-rot or pennywort, easily 
recognised among our native U. by its peltate leaves. 
Hydrolea Linn. Hydrophyllaceae. 12 sp. trop. Several have axillary 
thorns (branches). Fir. self-fertilising (cf. Phacelia). 
Hydromystria G. F. W. Mey. = Limnobium Rich. (H. stolonifera 
G. F. W. Mey. =Z. Boscii Rich.). 
Hydrophyllaceae. Dicotyledons (Sympet. Tubiflorae). 17 gen. with 
170 sp., chiefly in N. Am. where some of the gen. are in vigorous 
development; in S. Am., trop. As., Afr., &c. a few sp. occur, 
apparently the remnants of formerly wide-spread gen. Herbs or 
undershrubs with simple or compound exstip. leaves, radical, alt. 
or opp. Plant usually hairy. Firs, scattered or in cincinni like those 
of Boraginaceae, usually without bracteoles, $ , regular, usually 5- 
merous. K (5), imbricate, the odd sepal posterior; C (5), rotate, 
or bell- or funnel-shaped, usually imbricate; A 5, epipetalous and 
alternate with pets., often with scale-like appendages at base (see 
below); G (2), 1 — 2- loc., with 1 or 2 styles. Ovules on each cpl. 
00 — 2, sessile or pendulous, anatropous. Fruit usually a loculicidal 
capsule. Embryo small, in rich endosperm. The firs, in most 
investigated sp. are visited chiefly by bees ; honey is secreted below 
the ovary and protected by the appendages of the sta., which are 
frequently united to the corolla, sometimes (Hydrophyllum) form- 
ing tubes leading down to the honey. Fir. usually protandrous. See 
Phacelia. Chief genera: Hydrophyllum, Nemophila, Phacelia, Nama, 
Hydrolea. [Placed in Polemoniales by Benth. -Hooker, in Tubiflorae 
by Warming.] 
Hydrophyllum Linn. Hydrophyllaceae. 6 sp. N. Am. Fir. prot- 
androus, with the staminal appendages united to the corolla so as 
to form tubes through which alone the honey is accessible. 
Hydropyrum Link = Zizania Gronov. 
Hygrophila R. Br. Acanthaceae (iv. b). 30 sp. trop., in marshes. 
Hymenaea Linn. Leguminosae (11. 3). 8 sp. trop. Am. H. Courbaril 
L. is the West Indian Locust tree, a large tree with buttress roots 
(p. 40). The wood is valuable. From the stem exudes a resin (copal 
or anime) which is often found in lumps underground near the trees 
(cf. Agathis, Trachylobium) ; it is used in varnish, &c. 
Hymenocallis Salisb. Amaryllidaceae (1). 30 sp. trop. Am. The 
stipular appendages of the sta. are here united into a tube, on the 
summit of which the filaments stand, and which surpasses the perianth 
in conspicuousness (cf. Eucharis). 
Hymenopappus L’Herit. Compositae (vi). n sp. N. Am. 
Hymenophyilaceae. Filicineae Leptosporangiatae (Homosporous). 
