HAMAMELIDA CEAE 
419 
Hallia Thunb. Leguminosae (m. 7). 6 sp. S. Afr. 
Halocnexnum Bieb. Chenopodiaceae (7). 1 sp. Medit., Centr. As. 
Halogeton C. A. Mey. Chenopodiaceae (10). 5 sp. Medit., Centr. As. 
H . sativus Moq. the barilla, used to be burnt in Spain, &c. for soda. 
Halopeplis Bunge. Chenopodiaceae (7). 3 sp. Medit., &c. 
Halophila Thou. Hydrocharitaceae. 10 sp. trop. 
Haloragidaceae. Dicotyledons (Archichl. Myrtiflorae). 8 gen. with 
90 sp., cosmop., but chiefly Austr. Land, marsh, or water plants, 
herbaceous, of very various habit (see gen.), and with inconspicuous 
firs., solitary or in infl. The anatomy of the water forms is of interest, 
and also that of Gunnera, whose stem is polystelic. Fir. g or uni- 
sexual, usually bracteolate, regular, epigynous, usually 4-merous. 
Perianth in two whorls, or one, or absent. Sta. 8, obdiplostemonous, 
or fewer (down to 1 in Hippuris). Cpls. (1 — 4); ovary inf., multi- 
loc., with usually 1 pendulous anatropous ovule in each loc.; styles 
free. Nut or drupe. Embryo straight, in endosperm. Chief genera: 
Haloragis, Myriophyllum, Gunnera, Hippuris. The H. are undoubt- 
edly related to Onagraceae, as reduced forms. A gradual series may 
be traced, from the very complete fir. of Myriophyllum or Haloragis, 
down to that of Hippuris. Eichler and Warming also place the order 
in Myrtiflorae, whilst Benth. -Hooker add to it the Callitrichaceae and 
place it in Rosales. [Cf. Engler,Jahrb. 34, BeibL 79.] 
Halorageae (Benth. -Hooker) = Haloragidaceae. 
Haloragis Foist. Haloragidaceae. 50 sp. Austr., N. Z., Tasm., S.E. 
As., N. Am. Large herbs living in damp places. Firs. 4-merous 
throughout, obdiplostemonous. 
Haloxylon Bunge. Chenopodiaceae (10). 10 sp. N. temp, and sub-trop. 
Steppe plants of curious habit (rig. in Nat . PJl .). 
Hamamelidaceae. Dicotyledons (Archichl. Rosales). 18 gen. with 
50 sp. chiefly sub-trop. (N. and S.). The distribution areas of the 
genera (q.v.) are extremely disjointed, a fact probably due to the 
influence of the glacial period (p. 146 and Nat . />#.). They are 
closely allied to Cunoniaceae, and hence to Saxifragaceae. Trees 
and shrubs with alt., simple or palmate, stip. leaves. Infl. racemose, 
often a spike or head, frequently with an involucre of coloured bracts. 
Fir. g or unisexual, often apetalous, rarely naked, hypo- peri- or epi- 
gynous, usually without a disc. K 4 — 5, usually imbricate ; C 4 — 5, 
open or valvate, the petals often long and rolled up like a watch- 
spring in bud ; A 4 — 5 or rarely fewer ; G (2), usually median, rarely 
obliquely placed, with 2 styles, 2-loc. ; ovules 1 or more in each loc., 
pendulous, anatropous, with ventral or lateral raphe. Loculicidal or 
septicidal capsule. Exocarp woody, endocarp horny. Seed albu- 
minous, with straight embryo. Some sp. yield useful wood, resins, 
&c. Chief genera: Bucklandia, Liquidambar, Altingia, Fothergilla, 
Hamamelis. [Placed in Saxifraginae by Warming, in Rosales by 
Benth. -Hooker.] 
27—2 
