HOSACEAE 







\ Flowers in compound cymes, ovary 2-5-celled 

 ( x) Styles separate to the base; ripe carpels bony; sin 



or trees, mostly armed 

 m. Tall thorny shrubs or <■ rule 1 in each cell or 2 



unlike Crataegus 



n. Low shrub; 2 ovules in each cell, alike toneaster 



Styles united at the base; low unarmed shrub Arm 



2. Pistil one Prunus 



II. Herbs 



1. Flower nodding, rose purple Gturn 



2. Mowers erect, yellow or white 



a. Flowers yellow I'otenlilla 



b. Flowers while 



(1) Leaves basal; sepals seemingly 10 Fragaria 



(2) Leaves on the stem; sepals S Rubus 



f m 



Plate 10: A, Potentilla canadensis: B, Rubus parviflorus, i, flower, 2 fruit; C, Spiraea Van 

 Houttei, 1. flower, 2. fruit; 1). Geum ciliatum, 1. flower. 2. fruit; E, Amelanchier can- 

 adensis, 1. flower, 2. fruit; F. Prunus pennsvlvanica, 1. flowers, 2. fruit. 



Rubus -Blackberry, Raspberry 



rubus, bramblebush) 



PL 10. fig. B: 1, 2 



1. Stems herbaceous, trailing, unarmed 



2. Stems shrubby, more or less prickly 



a. Stems trailing or at least prostrate towards the ends 



b. Stems erect or arched ascending 



(1) Prickles stout; petals much exceeding the sepals 



(2) Prickles small : sepals and petals about the same length 

 x. Young stems with weak glandular bristles ; fruit red 

 y. Young stem with hooked prickles ; fruit black 



R. 



triflorus 



villosus 



allegheiiicusis 



strigdsus 

 dent&lis 



Rosa - -Ri >se 



l I. rosa, a rose) 



1. Leaflets 5-7 ; flower branches unarmed or nearly so h 



2. Leaflets 7-11; stems all densely prickly A 



Spiraea Spiraea 



(Gr. spiraea, perhaps originally from the twisted pods) 

 PI. 10, fig. C : 1. 2 



1. Corymbs terminating short leafy shoots : leaves lohed S 



2. Umbels sessile, subtended by a few small leaves ; leaves not lobed 5 



Si irbus — Mountain Ash 



i I.. Borons, service tree) 



1. Leaflets acuminate, smooth on both sides: fruit 4-6 mm. long S.omericdna 



2. Leaflets more or less obtuse, thicker : fruit 6-12 mm. long 



a. Leaflets pubescent below, especially along the veins : native 5". 



b. Leaflets always more or less pubescent on both sides: introduced S, 



bldnda 

 arkansdna 



I an Houttei 

 arguta 



samhucijolia 

 aucup 



