ROSE FAMILY 163 



There are about a dozen groves of Lyonothamnus floribundus on the easterly end of Santa 

 Catalina Island. They inhabit canons and grow on rocky ledges, always near the sea. In Swain 

 Canon near Avalon we have examined three groves. The lower grove is on a sharp hUlside about 

 200 feet above the canon bottom and consists of trees 20 to 35 feet high. The trunks branch 

 mostly in the top; they average 3 inches in diameter and are cyliadric, but upwards show a 

 tendency to become flattened or board-like, or triangular with three board-like wings, the longest 

 diameters being 6 to 13 inches. It is only occasionally that the divided type of leaf is noted in 

 this grove. Most of the original trees here were felled and the present stand represents crown- 

 sprouts. Very young crown-sprouts may be seen about the bases of some of the trunks. The 

 second or middle grove in Swain Canon occupies the rocky south wall and grows partly in the 

 canon bottom. One tree is 55 feet high and 12^4 inches in diameter at 2 feet above the ground. 

 The trunks are flattened as in the lower grove. A third or upper grove is found in a branch of 

 the canon to the left of the middle canon, going up. The trees are nearly as tall as in the middle 

 grove (Jepson Field Book 19:14-18, in 1908, ms.). 



In only two of the groves at the easterly end of Santa Catalina did Blanche Trask, the field 

 student of the island, find "compound" leaves, "yet a tendency towards divided leaves and im- 

 perfectly divided leaves is everywhere present", the strictly entire leaf being the exception rather 

 than the rule in most of the groves. At the westerly end of the island, the tree is much more 

 common, that region being "a veritable Lyonothamnus land" (cf. Blanche Trask, Erythea 7:141- 

 142). Every herbarium specimen of L. floribundus examined by us shows that all branchlets bear 

 at least one leaf and usually several with partially divided blades. Nearly all leaves of the simple 

 entire type show one or two reduced or supplementary lobes at base. The nearest approximation 

 to a specimen with strictly entire leaves is one in which a few of the leaves show only minute 

 supplementary lobes at the base of the main blade. 



In 1884 W. S. Lyon of Los Angeles collected material of this species on Santa Catalina 

 Island and sent it to Asa Gray who recognized the specimens as representing a new genus. That 

 island had been visited previously by thousands of persons and undoubtedly many had observed 

 and a number of them had gathered branches from these strange trees; but Lyon was the first 

 to make the tree kno^\Ti to botanists and is properly regarded as its botanical discoverer. The 

 genus is most closely allied to Vauquelinia Corr., especially through the species V. corymbosa 

 Corr. and V. californica Sarg. Vauquelinia occurs in New Mexico, Arizona, Mexico and Lower 

 California. The wood of Lyonothamnus is heavy, hard and strong. Our field notes show that it 

 has been used for making fishing poles and canes. 



Var. asplenifolius Bdg. Leaves regularly pinnately divided into 3 to 5 linear-lanceolate 

 segments, the segments asplenioid-pinnatifid with numerous rounded lobes. — San Clemente, Santa 

 Rosa and Santa Cruz islands. May-July. 



Locs. — Frey's Harbor, Santa Cruz Isl., A. L. Grant 1735; Pelican Bay, Santa Cruz Isl., 

 Mason 4109 ; San Clemente Isl., E. A. Mearns 4049 ; Santa Rosa Isl., T. Brandegee. 



Refs. — Lyonothamnus floribundus Gray, Proe. Am. Acad. 20:292 (1885), type loc. Santa 

 Catalina Isl., W. S. Lyon; Jepson, Man. 478 (1925). Var. asplenifolius Bdg. Zoe 1:136, 111, 

 pi. 5, figs. 8-13 (1890). L. asplenifolius Greene, Bull. Cal. Acad. 1:187 (1886), type loc. Santa 

 Cruz Isl., Barclay Hazard. L. floribundus f . asplenifolius Franceschi ; Bailey, Cyclop. Am. Hort. 

 961 (1900). 



2. PHYSOCARPUS Maxim. 



Deciduous shrubs with reddish-brown shreddy bark. Leaves simple; stipules 

 deciduous. Flowers white, in corymbs terminating lateral leafy branchlets. Calyx- 

 tube hemispheric. Calyx-lobes 5. Petals rounded, equal. Stamens 20 to 24. Pis- 

 tils 1 to 5, mostly 3, somewhat united toward the base, becoming as many inflated 

 2 to 4-seeded pods dehiscent along both sutures. Seeds with copious endosperm. — 

 Species 3, North America and Asia. ( Greek phusa, bellows or bladder, and karpos, 

 fruit. ) 



Stamens similar; carpels 3 to 5; cismontane 1. P. capitatus. 



Alternate stamens longer, their filaments with more dilated base; carpel 1 ; transmontane 



2. P. alternans. 



1. P. capitatus Ktze. Nine-bark. Erect or straggly shrub 3 to 5 feet high; 

 leaf-blades roundish or ovate, 3-lobed and irregularly serrate, glabrous, or stellate- 

 pubescent beneath, 1 to 3 inches long, on petioles % to 1% inches long; leaves of 

 sterile shoots similar but larger; corymbs hemispherical, % to 1 inch high; petals 

 11/2 to 2 lines long; pods divergent, commonly 3 to 4 lines long. 



Common along streams in the hills, or often gregarious on steep north slopes, 

 500 to 450 feet : Coast Ranges from the Santa Cruz Mts. to Siskiyou Co., 25 to 2500 



