ABSTKACTS. 



235 



11/1/1901). — A systematic paper; includes a large proportion of 

 novelties. — A. B. B. 



Plantae novae Americanse imprimis Glaziovianae. III. Edit. 

 I. Urban {Engl. BoL Jahrb. xxx. Beibl. 67, pp. 27-38 ; 12/3/1901).— 

 Contains a description of new species in the following orders : Guttiferae, 

 by \y. Euhlatid ; Proteaceae, Saxifragaceas, Eutaceae, Apocynaceae, and 

 Asclepiadaceae, by K. Schumann ; Meliaceae, by H. Harms ; and Amaran- 

 taceae, byG. Lopriore.— ^4. B. B. 



Plant Diseases : White Mould of Radish {Cystopus candidus), 

 and Notes upon Grape Mildew, &c. By B. D. Halstead 



{New Jersey Agri. Exp. St. Bept. ; two plates ; Oct. 1900). — Interesting 

 notes are also given on the spread of "rust " and the relation of same to 

 weather. — D. H. 



Plant Distribution in Southern California {Bei. Bot. Cent. 



bd. 10, ht. 3, p. 166). — A very interesting sketch, illustrated by six photos 

 and a sketch map, of the plant distribution in Orange County, California. 

 Prof. R. E. B. McKenney describes the following formations: 1. Mountain 

 formation. — This consists of closely grown scrub from 6 to 9 ft. in height ; 

 it is formed by species of Arctostaphylos, Quercus, Pentstemon, &c. In 

 patches in the dense scrub occur such plants as Clarkia pulchella, Pursh., 

 and Eschscholtzia californica, Cham. There are many climbers, chiefly 

 two species of Vicia. 2. Foot hills. — Also a scrub, but the plants are not 

 nearly so close, and generally only from 18 in. to 6 ft. in height. Some- 

 times the hillsides are covered with Cactus. In the open patches between 

 the shrubs there is a rich herbaceous vegetation which shows three distinct 

 sets of plants. The first set flowers in January, and consists of Nemophila 

 spp. and Gilia, &c. ; the second begins in March, and consists of Salvia 

 spp., Phacelia, &c., and especially Cuscuta subinclusa, which is especially 

 abundant ; the third, in April and in early May, consists of Allium 

 sp., Cotyledon spp., &c. 3. Canon formation. — Groves of trees {Platanus 

 racemosus and Quercus agrifolius) occur in the more sheltered places, and 

 a rich shrubby and herbaceous flora accompanies them {e.g. Claytonia 

 perfoliata, Phacelia Whitlavia, Mimulus luteus, and Galium Aparine). 

 4. River-bed formation. — Shrubs about 7 ft. high, chiefly Salix spp. and 

 Baccharis viminea. There are very few herbs in this region. 5. Mesa 

 formation. — The slightly elevated and comparatively level plain between 

 the eastern and western chains is characterised by an absence of all 

 arborescent and shrubby growth." It consists of succulent herbaceous 

 plants, and hard, dry, very often spinose forms (Sufeda, Atriplex, Cen- 

 taurea, &c.). 6. Bog formation. — Bulrushes, Watercress, a variety of 

 Scirpus lacustris and Azolla filiculoidcs are found in this, as well as 

 Apium graveolens and Cotula coronopifolia. 7. Strand formation. — 

 Generally herbaceous, but with a few low and spreading woody plants. 

 The vegetation is shown to depend on the water supply and the ground. 

 The annual rainfall is only from 12*28 to 31-87 at Los Angeles, and this 

 small rainfall and the alkaline nature of the soil explains the " semi- 

 desert " condition of most of the county. — G. F. S.-E. 



