ZEA 
631 
Zahlbrucknera Rchb. Saxifragaceae (1). i sp. Europe. 
Zalacca Rumph. Palmae (in. 5). 10 sp. Indo-mal. 
Zaluzania Pers. Compositae (v). 8 sp. Cent. Am. 
Zaluzianskya F. W. Schmidt. Scrophulariaceae (11. 7). 16 sp. S. Afr. 
Zamia Linn. Cycadaceae. 30 sp. trop. Am. 
Zamioculcas Schott. Araceae (1). 1 sp. trop. Afr., Bourbon. Leaves 
pinnate. 
Zannichellia Mich. ex. Linn. Potamogetonaceae. 1 sp. Z.palustris L., 
cosmop. It grows in fresh or brackish water, and has the habit of 
a small-leafed Potamogeton. Firs, monoecious ; the ? is terminal, 
and from the axil of its lower bracteole springs the $ . From the 
axil of the upper a new branch may arise, bearing % and $ firs, 
again. The $ fir. consists of 1 or 2 sta. , the $ of usually 4 cpls., 
surrounded by a small cup-like perianth. Pollination occurs under 
water as in Zostera, but the pollen is spherical. 
Zanonia Linn. Cucurbitaceae (1). 2 sp., Z. indica L. (E. Ind. to New 
Guinea) and Z. macrocarpa Blume (Sunda Is.). The latter has 
enormous flat winged seeds which float very well in the air, and are 
remarkably like the seeds of many Bignoniaceae. 
Zantedeschia Spreng. = Richardia Kunth. 
Zanthorhiza L’Herit. Ranunculaceae (2). 1 sp. Atlantic N. Am. 
Firs. 5-merous throughout, and polygamous. 
Zanthoxylum Linn. (incl. Fagara Linn.). Rutaceae (5). 170 sp. trop. 
and N. Am., As. Several are cultivated in shrubberies. Z. piperitum 
DC., the Japan pepper, yields fruits used as a condiment. The bark 
of Z. fraxineum Willd. (prickly ash or toothache-tree) is used in Am. 
as a remedy for toothache. The prickly stems of Z. Clava-Herculis 
L. are used as walking sticks. 
Zauschneria Presl. Onagraceae (11). 1 sp. Calif., Mexico. 
Zea Linn. Gramineae (1). 1 sp., Zea Mays L., the maize or Indian 
corn, apparently originally a Mexican sp., but now cultivated in most 
trop. and subtrop. regions. It is a tall annual grass, with terminal 
$ infl. and ? infls. in the axils of the foliage-leaves. The <? spikelets 
are borne in pairs, and are 2-flowered. The ? infl. forms a * cob’ with 
long filamentous stigmas hanging out at the end (the firs, are polli- 
nated by wind). The cob is enveloped when young by large spathe- 
leaves, and consists of combined spikes ; each two rows of firs, visible 
on its surface correspond to one spike of firs. The cultivated forms 
are 8-, 10-, 12-, or 24-rowed. This should be compared with 
Euchlaena, in which the spikes are distinct and form a tuft. Each 
spike consists of one-flowered spikelets. The fruit is the familiar 
maize-seed, in which the structure of a grass-fruit can easily be made 
out ; the embryo occupies the white portion near the pointed end. 
Next to rice, maize is the most important cereal ; it is termed corn 
in the U.S., like wheat in England, oats in Scotland. The grain is 
made into flour (Indian meal) or cooked without grinding ; green corji 
