Hybridization 



OF BOTANICAL TERMS. 



Hypnospore 



Hybrid is often erroneously 

 used to designate the result of 

 cross-fertilization between any 

 different species or varieties. 

 Astruehybridsareoften sterile, 

 the term " mule" has been ap- 

 plied to them. Burbidge pro- 

 poses to retain the term " mule" 

 for sterile hybrids only. See 

 Genus-hybrid. 



HYBRIDIZATION, the fertiliza- 

 tion of a flower by pollen from 

 a plant of another species. 

 Often erroneously used for 

 cross-fertilization in general. 



HY'DROID, see Tracheid. 



HYDROPHILOUS, having the 

 pollen conveyed to the stigma 

 by means of water. 



HY'DROPHYTE, an aquatic plant 

 of any kind. 



HYDROTROPISM, power in a 

 growing organ of turning 

 in a detinite manner or direc- 

 tion through the influence of 

 moisture, i.e. of taking a 

 definite position with respect to 

 the source of moisture. See 

 Positive and Negative Hy- 

 drotropism. Compare Hy- 

 groscopic. 



HYE'MAL, see Hibernal. 



HYGROMETRIC, moving in a 

 definite manner as a result 

 of a change in the degree of 

 moisture ; hygroscopic. 



HYGROPH'ANOUS, having a 

 watery appearance. 



HY'GROPlASM, the fluid portion 

 of the protoplasm. Compare 

 Stereoplasm. 



HYGROSCOPIC, (1) absorbing 

 moisture with avidity; 

 (2) showing an increase or 

 diminution of moisture by mo- 

 tion; hygrometric. Compare 

 Hydrotropism. 



HYGROSCdP'iC gEXLS, certain 

 cells in the leaves of grasses 



which have the power of alter- 

 ing their form under the influ- 

 ence of moisture and causing 

 the leaves to "curl" in dry 

 weather. From their bladder- 

 like appearance they are also 

 called Bulliform Cells. 



HYME'NltJM (pi. Hyme'nia), a 

 spore-bearing surface in fungi, 

 especially in mushrooms and 

 their allies. 



HYMENOPHORE, the portion of 

 a sporophore immediately be- 

 neath a hymenium; hymen- 

 ophorum. 



HYMENOPH'ORUM, see Hymen- 



OPHORE. 



HYPAN'THltJM, an expanded, 

 usually fleshy, receptacle, 

 more or less enclosing the 

 flowers, as in the fig, rose, 

 Dorsteuia and Ambora; hy- 

 pauthodium. See Hip and 

 Syconus. Compare Clinan- 

 thium and Receptacular 

 Tube. 



HYpANTHO DIUM, see Hypan- 



THIUM. 



HYPERBOREAN, growing in the 

 extreme north. 



HYPERTROPHY, excessive de- 

 velopment. Compare Atro- 

 phy. 



HY'PHA (pi. Hy'phae), a filament 

 of mycelium. 



HYPHAs'MA, an old term for 

 mycelium, still occasionally 

 used when particularly deli- 

 cate and web-like. 



HYP'NOSPERM, an asexually pro- 

 duced restiug-spore in algae; 

 hypnospore. 



HYPN0SP6rAN'GIUM, a sporan- 

 gium containing resting-spores. 



HYPNOSPORE, any resting- 

 spore, especially one produced 

 asexually. Compare Hypno- 

 sperm. See Resting-spore. 



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