ROSACEA. 



275 



of pistillate heads similar, the pistils with interspersed clavate trun- 

 cate bracts; ovary 1-ovuled; style one, filiform, laterally stigmatic. 

 Fruit a coriaceous nutlet with tawny hairs about the base. Seed 

 orthotropous, pendulous. 



1. PLATANUS L. Plane Tree. 

 The only genus. (Greek platus, broad, referring to the ample 

 leaves.) 



1. P. racemosa Nutt. Sycamore. Widely branching, 50 to 80 

 ft. high; leaves stellate-pubescent when young, broader than long, 

 5 to 6 in. broad, mostly 5-lobed, at base truncate or subcordate; 

 lobes acute, the lower pair smaller; margin entire, save for the remote 

 small and blunt cusps terminating the main veins; pistillate heads 

 3 to 5; staminate heads several. 



Common tree along all large interior streams, ranging from the 

 Sacramento and San Joaquin Rivers westward through the Mt. 

 Diablo Range to the eastern slope of Bald Peak near Berkeley, 

 Alameda Creek near Niles, Los Gatos Creek, Carnadero Creek near 

 Gilroy and southward through the Coast Ranges to Southern Cali- 

 fornia. Not in the North Coast Ranges so far as known to us. Mar. 



63. ROSACE/E. Rose Family. 



Herbs, shrubs, or trees. Leaves alternate, toothed or divided, ours 

 with stipules. Flowers solitary or in spikes, racemes, or cymes. 

 Calyx 5 (or 4)-lobed. Petals 5, rarely none. Stamens 10 to numer- 

 ous, usually indefinite, inserted with the petals on the calyx below 

 its lobes. Pistils 1 to many, distinct and free from the calyx, or 

 united into a 2 to 5-celled ovary which is nearly or completely 

 inferior. Fruit a follicle, an achene, a drupe, a cluster of drupelets 

 (as in a blackberry), or a pome. Seeds with straight embryo; endo- 

 sperm usually none. Calyx in certain genera appearing double by 

 a row of bractlets borne at or near the sinuses. 



A. Ovary superior. 



Fruit dehiscent, consisting of 2 to 5 follicles; shrubs with simple leaves.— 

 Spire* (Meadow Sweet Tribe). 

 Follicles dehiscent by both sutures, several-seeded; flowers in corymbs. . 



1. Opulaster. 



Follicles dehiscent by the dorsal suture or indehiscent, 1-seeded ; flowers 



in panicles 2. Holodiscus. 



Fruit indehiscent, consisting of 1 to many achenes or composed of drupelets 

 and styled a " berry."— Rose*: (Rose Tribe). 

 Shrubs 



Leaves simple; pistil 1, becoming an achene. 

 Petals white; leaves linear and rigid; achene not tailed 



3. Adexostoma. 



Petals none; leaves broadly obovate; achene with long plumose tail.. 



4. Cercocarpus. 



Leaves pinnately compound; pistils many, disposed on the inside of a 

 globose or urn-shaped calyx-tube which is lined by the receptacle 

 and in fruit termed a "hip; " stems prickly .... 5. Rosa. 



Leaves simple or compound ; pistils many on a convex receptacle, 

 becoming drupelets which are coherent and form the fruit called 

 a " berrv " 6. Rubus. 



