392 HYDRANGEACEAE 



Family 58. HYDRANGEACEAE. Hydrangea Family. 



Shrubs or trees, or rarely vines. Leaves opposite, without stipules. Flow- 

 ers commonly perfect, in cymes. Hypanthium well developed, usually 

 ribbed. Sepals 4-10. Petals as many. Stamens from 8 to many. Gynoe- 

 cium of 2-5, rarely 10, united carpels. Ovary partly or wholly inferior; 

 styles distinct or united, sometimes wanting. Fruit a capsule. 



CaDSule obovoid or obconic, the beaks rising abruptly from the body. 



1. Philadelphus. 

 Capsule conic or ovoid, the beaks tapering gradually from the body. 

 Filaments and anthers unappendaged : sepals and petals 5. 



Leaf-blades toothed; hypanthium short during anthesis. 2. EnwiNiA. 



Leaf-blades entire; hypantliium long during anthesis. 3. Fexdlerella. 



Filaments aopendaged under the anthers; anthers appendaged at the top: sepals 

 and petals 4. 4. Fendler.\. 



1. PHILADELPHUS L. Mock Orange, Syringa. 



Branching shrubs. Leaves toothed or entire. Flowers perfect, borne at 

 the ends of short leafy branches, solitary or in cymes. Sepals 4, rarely 5, valvate, 

 per3istent, more or less tomentose within. Petals 4, rarely 5, convolute, white 

 or ochroleucous. Stamens usually many, 25-60; filaments flat, subulate, free 

 or more or less united below; anthers short, didymous. Ovary at least two-thirds 

 inferior and adnate to the hypanthium, 4-celled; styles elongate, distinct or more 

 or less united; stigmas distinct or more or less united. Ovules numerous, pendu- 

 lous. Capsule more or less woody, loculicidal, the septa separating in the cen- 

 ter. Seeds numerous; coat reticulate; albumen fleshy. 



Leaf-blades tliin, not leatherj', usually toothed or denticulate, more than 3 cm. long; 

 flowers several. 

 Petals ovate-lanceolate, acute or obtuse at the apex. 1. P. Helleri 



Petals oblong to rounded-oval; rounded at the apex. 



Leaf-blades 3-5-ribbed. the lateral ribs or if 5-ribbed the second or stronger pair 

 meeting the midrib some distance from the base of the blade. 

 Bark of the second season red or chestnut-brown, with conspicuous cross- 

 cracks, at last peeling off. 2. P. Lewisii. 

 Bark of the second season gray or yellowish, neither cross-cracked nor peehng 

 off. 3. P. columbianus. 

 Leaf-blades 5-ribbed, all ribs originating at the base of the blade. 



4. P. Gordonianus. 

 Leaf-blades small, 0.5-2 cm. long, entire; flowers mostly solitary. 



Hypanthium 4-5 mm. high. 5. P. viicrophyllus. 



Hypanthium about 2 mm. high, or in fruit 3-4 mm. high. 



Styles wholly united or nearly so; stigmas sometimes also partly united. 



6. P. occidentalis. 

 Styles distinct for at least half their length; stigmas distinct. 



7. P. minutus. 



1. P. Helleri Rydb. Shrub 2-3 m. high, with ascending branches; bark of 

 the young branches brownish, glabrous, and of the second year yellowish or gray, 

 not exfoliating; leaf -blades ovate or lance-ovate, denticulate or rarely entire, 

 4-7 cm. long, glabrous, or sparingly hairy along the veins beneath; flowers 5-11, 

 falsely racemose; sepals 7-8 mm. long, short-acuminate; petals white, 15-18 mm. 

 long; styles united to near the apex. Hills: Ida. Submont. Jl. 



2. P. Lewisii Pursh. Shrub 1-2 m. high, with ascending branches; bark 

 of the young twigs red, glabrous; leaf -blades ovate-lanceolate or ovate, glabrous 

 above, hairy on the veins and in their axils beneath, entire or denticulate; sepals 

 lance-ovate, abruptly acuminate; petals white, 10-15 mm. long; styles united 

 half their length; capsule about 1 cm. long. (?) P. intenncdius A. Nels. River 

 banks and hihs: B.C. — Mont. — Ida.— Ore. Submont.— -Mont. My-Jl. 



3. P. columbianus Koehne. Shrub 2-3 m. high, with ascending branches; 

 bark of the young twigs mostly yellowish, glabrous or pubescent; leaf-blades 

 lanceolate to ovate, more or less acuminate, denticulate or entire, more or less 

 hairy on both sides; flowers 3-9, falsely racemose ; sepals lance-ovate, acuminate; 

 petals white, 15-20 mm. long; styles united half their length; capsule about 12 

 mm. long, somewhat 4-angled below. River banks and copses: B.C. — Ida. — • 

 Calif. Submont. My-Jl. 



