HUM ULUS 
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Family 2. CANNABACEAE. 
Cannabaceae Engler Fiihrer 33 (1886); Cannabineae Gaudichaud Voy. Aut. Monde 507 (1826); Canna- 
boideae Engler in Pflanzenfam. iii, pt. i, 96 (1894); Ascherson und Graebner Syn. iv, 595 (1911). 
Herbs, strong-smelling owing to the presence of numerous glands, without latex. Leaves, 
palmatinerved ; lower ones opposite and decussate ; upper ones usually alternate ; stipulate. Petioles 
long. Laminae palmatinerved, more or less divided, more or less hairy. Inflorescences dioecious, 
of compound cymes. Staminate inflorescences larger than the pistillate ones, lax-flowered. Pistillate 
inflorescences dense-flowered. Flowers wind-pollinated, protogynous. Bracts persistent ; of the stami- 
nate flowers small, subulate. Perianth of the staminate flowers with 5 deeply cut segments ; of 
the pistillate flowers entire or with a slit on one side, persistent, adhering to the fruit. Stamens 5, 
short, straight. Filaments short, erect in bud, attached to the base of the sepals. Ovary of 2 
superior, united carpels, with 1 loculus, 1 ovuled. Stigmas 2. Ovules pendulous, anatropous, becoming 
curved. Fruit an achene. Embryo curved or rolled. 
2 genera and 3 species ; north temperate zone. 
Genera of Cannabaceae 
Genus 1. Humulus (see below). Perennial. Stem twining. Laminae palmatilobed, cordate. 
Pistillate inflorescences peduncled. 
Genus 2. # Cannabis (p. 98). Annual. Stem erect. Laminae palmatisect. Pistillate 
inflorescences sessile. 
Genus 1. Humulus 
Humulus L. [Gen. Plant. 304 (1737)] Sp. PL 1028 (1753) et Gen. PI. ed. 5, 453 (1754); Engler in 
Pflanzenfam. iii, pt. i, 96 (1894). [Lupulus Tournefort Inst. 535, t. 309 (17P9); Miller Abr. Gard. Diet. ed. 4 (1754).] 
Herbs with perennial rhizomes, twining stems, and yellow glands. Stems turning to the right, 
with small hooked prickles. Stipules large, ovate-acute. Laminae palmatilobed. Peduncles of 
pistillate flowers curved. Bracts of two kinds: (1) outer or stipular “bracts” each bearing 
2 flowers, the lateral axis suppressed ; (2) inner or true bracts, each with 1 flower, at first shorter 
than the outer ones, ultimately larger and projecting beyond them, imbricate, suborbicular. Stigmas 
linear-acute. Seeds frequently not formed, as the staminate and pistillate plants rarely grow together. 
Embryo spirally coiled. 
2 species ; north temperate zone. Only British species, H. lupulus. 
I. HUMULUS LUPULUS. Hop. Plate 106 
Lupulus salictarius Gerard Herb. 737 (1597) including L. sylvestris ; L upulus mas et foemina Ray Syn. ed. 3, 
137 (1724)- 
Humulus lupulus L. Sp. PL 1028 (1753); Syme Eng. Bot. viii, 133 (1868); Rouy Ft. France xii, 269 
(1910); Ascherson und Graebner Syn. iv, 596 (1911); Lupulus humulus Miller Gard. Diet. ed. 8, no. 1 (1768). 
leones: — Smith Eng. Bot. t. 427; FI. Dan. t. 1239; Reichenbach Icon, xii, t. 656, fig. 1326. 
Camb. Brit. FI. ii. Plate 106. (a) Shoot with pistillate catkins. ( b ) Shoot with staminate flowers, 
(c) Pistillate flowers (enlarged). ( d ) Staminate flowers (enlarged), (e) Fertile shoot in autumn. (/) Mature 
bracts and fruits. Cambridgeshire (E. W. H.). 
Exsiccata : — Billot, 2741 ; Herb. FI. Ingric. v, 577. 
A twining herb up to about 5 m. high. Rhizome stout, branched. Stem subhispid. Stipules 
united in pairs. Petioles about half as long as the laminae, stout. Laminae — lower ones cordate, 
5-lobed, lobes ovate, with large simple serrations, up to about 10 cm. long and nearly as broad ; 
upper ones ovate, subcordate at the base, serrate, acute. Pistillate inflorescences peduncled. 
Hedgerows and near houses and cottages ; perhaps indigenous in southern England ; as a relic 
of cultivation, it occurs northwards to Elginshire ; ascending to about 300 m. in Scotland, though 
rare and not indigenous at such altitudes. Established in most of the southern counties of Ireland, 
rare and not indigenous in the north. 
M. 11. 
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