50 POMACEAE 



* Cells of the ovary apparently twice as many as the styles. 

 Amelanchier. With us the only genus. 



. PYPyUS L. Small trees or shrubs, with toothed or lobed leaves, and fra- 

 grant flowers in simple terminal cymes. Calyx urn-shaped. 5-eleft. Petals 5, 

 roundish. Stamens many. Styles 2-5. Fruit a pome, with the central por- 

 tion papery, 2-5-celled, each cell 2-seeded. 



P. ioensis (Wood) Bailey. Western Crab Apple. A small tree, 10-15 feet 

 high, bushy, often spiny; leaves ovate, oval or oblong, dentate or crenate, or 

 often with a few rounded lobes, obtuse, white-pubescent beneath, mostly 

 glabrous above; flowers white to rose-color, appearing with the leaves; fruit 

 globular, about an inch in diameter, green, sour. Thickets; May; common. 

 Usually labled P. coronarla L. ( P. coronarla var. ioensis Wood. Malus ioensis 

 (Wood) Britton.) 



P. malus L. Common Apple. This species is becoming a frequent escape 

 along roadsides and in waste places. Observed in Appanoose; Decatur, Ring- 

 gold Union, Adams, Page, Montgomery, and Pottawattomie counties. 



CRATAEGUS L. Thorny trees or shrubs, with alternate petioled serrate 

 lobed or pinnatifid leaves, and usually white flowers in terminal corymbose 

 clusters. Calyx urceolate or cainpanulate, limb 5-cleft. Petals 5. Stamens 

 many. Ovaries 1-5, with corresponding number of styles. Pome drupe-like, 

 containing 1-5 bony carpels. 



* Leaves obovate, spntulate or oblaneeolate. 



C. crus-galli L. Cockspur Thorn. Shrub or small tree, 8-25 feet high; 

 branches grayish, horizontal; thorns long and slender; leaves cuneate-obo- 

 vate, coriaceous, dull green, glabrous on both sides, serrate above the middle; 

 corymbs many-flowered, pedicels and calyx glabrous; fruit globular. Thick- 

 ets; May; common. 



C. punctata Jacq. Similar to the preceding; leaves obovate. short-point- 

 ed or obtuse, cuneate toward the base and entire below, irregularly serrate, 

 slender petioled, glabrous above, mostly pubescent beneath; corymbs many- 

 flowered; calyx and pedicels mostly pubescent; fruit globose or oval. Thick- 

 ets; May; frequent; Allamakee, Fayette, Webster, Story, Cerro Gordo, and 

 Emmet counties. 



* * Leaves ovate or broadly oval or somewhat orbicular. 

 t Leaves pubescent, especially on the veins beneath. 



C. mollis (T. & G.) Scheele. A small tree or shrub, 10-25 feet high; leaves 

 usually broadly ovate, base truncate, incised, sharply serrate, teeth gland- 

 tipped, rough above, very pubescent beneath; twigs, petioles, pedicels, and 

 calyx densely pubescent. Bich woods, thickets; April-May; common. (C. 

 coc.cincn var. mollis T. & G.) 



C. tomentosa L. Banging from 10-25 feet high; spines stout; leaves ovate- 

 oval or broadly oval, acute or acutish, sharply serrate, frequently incisely 

 lobed, base tapering or cuneate, petioles margined; twigs, shoots, and lower sur- . 

 face of the leaves, especially along the veins pubescent or villous-pubescent; 

 flowers small, ill-scented. Lowlands woods, thickets; May-June; frequent, 

 f f Leaves glabrous or nearly so; teeth mostly gland-tipped. 



C. rotundifolia (Ehrh. ) Barck. A shrub or small tree similar to the pre- 

 ceding, but with slender spines, and mostly smaller leaves which are oval or 

 obovate, slender-petioled, glabrous or nearly so, base tapering or cuneate, in- 

 cised-serrate or somewhat lobed. Uplands; April-May: infrequent; Johnson 

 county. 



