80 Kansas Academy of Science. 



178. Thuya (Biota) sibirica Ende. Siberian Arbor-vitse. A very hand- 

 some and apparently hardy species (or variety); only recently introduced; 

 gives good promise. 



179. Chamaecyparis thyoides B. S. P. (Britton, Stern and Poggenburg). 

 Southern White Cedar. Sparingly planted; does fairly well for wind- 

 breaks. 



180. Cupressus sempervirens L. Cypress. Occasional in cemeteries. 



181. Taxodium distichum L. C. Richard. Bald Cypress. Leaves an- 

 nual. Occasional in parks ; endures the climate well ; less of the twigs 

 freeze than are cast off by ordinary annual self-pruning. Several trees in 

 Topeka, planted forty years ago, are eight and one~half decimeters around 

 the trunk snd fifteen meters high. Frequently collected by students who 

 mistake the trees for native. 



182. Retinospora plumosa Siebold. Oriental Cypress. Occasional in 

 cemeteries. 



183. Cryptomeria japonica D. Don. Japan Cedar. In cultivation. 



Order XV. PINALES. The Pines and their Allies. 



Resinous evergreen trees, with acicles for foliage, these consisting ot 

 elaminate, single linear or scale-like, or fascicled acicular or awl-shaped, 

 leaves, in this case representing leaf-petioles that are segmented or split in 

 prefoliation, and popularly called "needles," of one (deciduous), two, or sev- 

 eral years' duration. Pollen-grains or androspores bilobed, apparently 

 triple, and consisting of one generative cell carrying two antherozoids or 

 sperms, one large central vegetative cell, and two lateral gas-filled wing- 

 sacs, which serve to buoy the androspore long distances through the air, 

 and to orient it on approaching an ovule (gynosporangium) on another tree; 

 while the vegetative cell serves to nourish the generative cell in its germi- 

 nation in order to facilitate fecundation. Electrical conditions within cer- 

 tain limitations of distance furnish the stimuli that guide the spore to its 

 required destination, thus eliminating chance to a certain extent. 

 Family 31. Pinace^. Pine Family. 



Trees with acerose leaves (acicles or needles) singly or in fascicles of 

 two to five in each fascicle, with their bases enclosed in a modified scaly 

 basal sheath (perifascicle) ; perifascicular scales imbricated, usually in four 

 ranks, the final scales often long and fimbriated. When two leaves are in a 

 fascicle a cross-section of each is semiterete; when three or five, the form 

 is a sector of a cylinder, corresponding to the number of leaves. Tracheids 

 in the wood each of many elongate-polyedral cells taperingly spliced end to 

 end, in rectilineal radial ranges, each provided with four to six vertical 

 rows of circular membrane-covered (cellulose) pits for osmotic action of the 

 sap from cell to cell; resin-ducts large, equal to from fifteen to fifty cells, 

 scattered mostly through the late-season wood. Fruit a cone, formed of 

 numerous imbricated suberoid scales upon a conical receptacle. Ovules two, 

 in the axil of each scale, each eight-celled. Cotyledons in the embryo 

 acicular, 8-12. 



185. Araucaria imbricata Willdenow. Norfolk Island Pine; "Monkey- 

 puzzle." Dioecious. Raised in houses and out; not hardy, though becoming 

 quite frequent. 



