Monocotyledones
KEY TO FAMILIES
Key
1
Plant floating free on fresh water, composed of oval green platelets budding from lateral pouches
6
Fls zygomorphic, us. strongly, with one petal differentiated as labellum; central bilaterally symmetric column bearing 1–2 stamens and, on the side facing the labellum, a stigmatic surface
10
Lvs oblong to elliptic, spaced along slender stem; petiole short, narrow, twisted to bring smooth convex abaxial lf-surface uppermost
Stem stout to slender, us. completely hidden within lf-bases; lvs us. not strongly fibrous
12
Fls unisexual in capitula on simple or branched infls; capitula all globose, lower ones female, upper male
14
Per.-segs 4; lvs mostly broad, if linear wholly aquatic and permanently submerged
Infl. a ∞-fld cyme, much-branched to condensed, or fls sts solitary; floral bracts present
Lvs with well-developed lamina, or if reduced to sheathing bracts these few and mostly basal; plants rarely dioec
18
Lvs ± jointed at junction of lamina with sheath, us. with definite projecting ligule; spikelets distichous; each fl. associated with 2 bracts, one below, one above
23. GRAMINEAE
Lvs not jointed at junction of lamina with sheath; ligule if present not projecting; spikelets distichous or cylindric; each fl. in axil of a single bract, or occ. ebracteate
19
Fls grouped in simple spikelets; each fl. subtended by a bract (glume) which is visible without dissection of infl.
Fls grouped in a complex, ± spike-like infl. within 2–3 glume-like bracts; individual fls either without subtending bracts or enclosed in a hyaline scale only visible by dissection
Lvs flaccid and incapable of standing erect without support of water; infls small and inconspicuous
21
Fls borne on a flattened axis permanently enclosed in a spathe-like lf-sheath; marine, intertidal to subtidal
22
Infl. a 2-fld spike; ripened carpels long-stalked, ± umbellately arranged at top of long spirally twisted peduncle
Infl. of 1-several fls; frs short-stalked, apparently axillary, solitary or in small clusters
KEY TO GENERA
(Gramineae appear only as a Family. For a full key to Orchidaceae see p. 104; only a few genera of orchids come out separately here.)
Key
2
Lvs pinnately compound
GROUP A RHOPALOSTYLIS
3
Lf bearing hairs, short to long and sts inconspicuous; or lf wholly or partly covered with appressed scales
GROUP B 7
4
Per. petaloid, us. white or coloured
GROUP C 15
5
Lf-margins not at all scabrid
GROUP D 26
Lf-margins scabrid to the touch, either throughout or near tip only
GROUP E 45
6
Plant with chlorophyll; stems green, sts with admixture of tawny colours
GROUP F 57
Plant without chlorophyll; stems mostly white or dull brown, never green
GROUP G 69
GROUP B
Lvs simple, bearing short or long hairs, or appressed scales
Key
12
Stems hollow; spikelets distichous and very rarely solitary, sts 1-fld
GRAMINEAE
Fls in a solitary, complex but superficially spikelike infl. enclosed within 2 almost opp. glumelike bracts
14
Tepals all membr., connate below into a cup-shaped tube; lf-sheath not keeled, crescentic in T.S.; plants too large to be turf-forming
Tepals either fleshy or, if membr., free almost to base; lf-sheath us. keeled and ± V-shaped in T.S. except in very small turf-forming spp.
GROUP C
Lvs simple with well-developed laminae, glab., but margins and nerves may be scabrid; per. petaloid
Key
19
Staminal filaments ornamented with hairs; infl. us. an openly branched panicle, if reduced and ± raceme-like then an occ. bract subtends 2 fls.
Staminal filaments glab.; infl. us. truly racemose or of only 1–2 fls, if paniculate then narrowly so and almost woody
23
Plant resembling a small rhizomatous grass; per. spread out almost flat, blue to white
Plant composed of crowded fans of large, excessively fibrous lvs; per. narrow-elongated, greenish to dull red
GROUP D
Lf simple, sts stem-like, glab., margin not scabrid; per. either not petaloid, or absent
Key
28
Plants of sites below regular high tide mark, us. forming grass-like sward; lvs linear but not filiform, with ∞ transverse veinlets at right angles to midrib and strong marginal nerves
Plants of brackish or fresh water; lvs us. distributed on slender stems, or, if closely crowded, almost filamentous, without ∞ transverse veinlets and strong marginal nerves
31
Fls bisexual, tetramerous, ∞, in obvious, fully exserted, continuous or interrupted spikes.
40
Lvs mostly linear with marginal sclerenchyma, us. keeled and ligulate
GRAMINEAE
Lvs mostly linear-filiform to terete or trigonous, a few equitant and iris-like, almost all eligulate
Lvs erect, either with broad flat lamina, or terete with septa visible externally or internally
43A
43A
Fr. with hard bony endocarp and ± spongy, thick or thin mesocarp, sessile or scarcely stipitate
Fr. with thin brittle pericarp, distinctly stipitate
Floral bracts (2)–3, each clearly overtopping the one below; lf-sheaths opaque, light brown
GROUP E
Lvs simple, sts stem-like; margins scabrid throughout or near tip only; per. not petaloid
Key
45
Plant a root-climber attaching itself by coarse aerial roots produced from thick, hard but brittle stem
46
Lf ± jointed at junction of lamina with sheath, us. with definite projecting ligule
GRAMINEAE
Glumes spiral; compound infls long; subinfls sessile and mostly confluent, ± spirally arranged
54
Lvs similar to stems; hypog. scales attached to nut and falling with it; plants erect, of coarse tufted habit
Lvs unlike stems; hypog. scales remaining attached to stem after nut falls; plants low-growing, forming dense or loose cushions
GROUP F
Lvs 0 or reduced to sheaths; plant with chlorophyll
Key
GROUP G
Lvs 0 or reduced to scales or sheathing bracts; plants without chlorophyll
