Keys in Flora of Bhutan:
1. Plants with stinging hairs (in Dendrocnide conspicuous only on inflorescences); cystoliths punctate …… 2
Plants without stinging hairs; cystoliths linear or punctate ………………… 5
2. Leaves opposite …………….. 2. Urtica
Leaves alternate ………… . …… 3
3. Leaves deeply palmately lobed … ……. … 5. Girardinia
Leaves unlobed .. ……………………….. . . … .. 4
4. Annual herb; leaves serrate; achenes reflexed against winged pedicels ….  3. Laportea
Shrub or small tree; leaves entire, crenate or sinuate; achenes not reflexed, pedicels unwinged ……. 4. Dendrocnide
5. Leaves pinnately veined to base, lowermost lateral veins not stronger than others ……… …… 6
Leaves 3-veined at base, sometimes pinnately veined in upper part but then lowermost lateral veins distinctly stronger than others …. 9
6. Small herb up to 50 cm, leaves linear, in whorls of 3 or 4 …. 6. Pilea (P. ternifolia)
Subshrubs, shrubs, small trees or woody climbers, 50 em or more, leaves elliptic, alternate . …… 7
7. Succulent-stemmed subshrub 0.5-2 m, with minute, caducous, opposite leaves when young, leaves shallowly crenate-serrate in upper half, petioles 5-7 mm ……………. 9. Procris
Shrub, small tree or woody climber, 5 m or more, without minute opposite leaves, leaves entire, petioles 1.5- 9 cm . ….. .. . 8   
8. Shrub or small tree; leaves with punctate cystoliths; flower clusters up to 3 mm diameter, forming small cymes 1- 3 cm long, stigma brush-like, sessile …. 14. Oreocnide (O. rubescens)
Large woody climber; leaves with linear cystoliths; flower clusters 3-15 mm diameter, forming robust cymes 2.5- 5 cm long, style linear  …. 1. Poikilospennum
9. Leaves usually asymmetric and oblique at base; cystoliths linear; stipules usually axillary; female perianth with often 3 or sometimes 4-5 unequal segments, rarely absent in some Pilea species . . . …. .. . 10
Leaves symmetric, not oblique at base; cystoliths punctate; stipules usually lateral, or if axillary then deeply bifid, absent in Parietaria; female perianth tubular, minutely 2- 4 toothed, dry or fleshy, reduced to a fleshy basal cup in Oreocnide and absent in Maoutia ……… .. 12
10. Leaves alternate, rarely with minute opposite leaves (modified stipules); flowers borne on bracteate, often fleshy, receptacles, more rarely in cymes …. 8. Elatostema
Leaves opposite, sometimes in unequal pairs (but then flowers in panicles); flowers in cymes or panicles, more rarely in globose heads or subumbellate, in Lecanthus on broad flat receptacle ………………… 11
11. Flowers borne in fleshy, plate-like receptacle on long, simple peduncle 7. Lecanthus
Flowers in axillary dichotomous cymes or panicles, more rarely in globose heads or subumbellate …. …… 6. Pilea
12. Herbs, often prostrate or decumbent, less than 1 m tall, leaves usually opposite, alternate only in Pouzolzia ………. 13
Erect shrubs or trees 1 m or more tall, leaves usually alternate, opposite only in Boehmeria …………. 15
13. Leaf margins serrate …………. . 11. Chamabainia
Leaf margins entire …………. .. …… 14
14. Diffuse weak herbs; leaves petiolate, always opposite; flowers subtended by linear bracts; stigma brush-like, sessile . … .. . .. 17. Parietaria
Decumbent or suberect often wiry herbs, leaves sessile or sometimes petiolate, opposite or alternate, flower clusters with ovate bracts; style filiform ….. 12. Pouzolzia
15. Underside of leaves white tomentose or densely white pubescent . . . .. ……… 16
Underside of leaves green or pale green, never white ………………………. 22
16. Flower clusters sessile, axillary or forming simple spikes ……………. . . . . … 17
Flower clusters forming cymes or panicles, never sessile and axillary or in simple spikes …… .. 18  
17. Leaves shallowly crenulate or serrulate; flower clusters borne only on leafless spikes, never axillary; style persistent in fruit …… 10. Boehmeria (B. rugulosa)
Leaves sharply serrate; flower clusters mostly axillary, sometimes also forming leafless spikes; style deciduous in fruit  12. Pouzolzia (P. sanguinea var. fulgens)
18. Leaves suborbicular, apiculate; flower clusters in lax cymes 3- 9 cm long … 19
Leaves elliptic, narrowly ovate or lanceoli:He, acuminate; flower clusters in short cymes l – 4 cm long or rather rigid panicles 4- 7 cm ………… 20
19. Shrub with coarsely crenate-serrate leaves; style filiform, persistent; achenes enclosed by dry perianth . . ……. 10. Boehmeria (B. nivea)
Tree with sinuate-dentate leaves; stigma brush-like, sessile; achenes enclosed by fleshy perianth ……………. 15. Debregeasia (D. wallichiana)
20. Leaves ovate-elliptic, coarsely dentate-serrate; perianth absent in female flowers; achenes dry ……. …. … 16. Maoutia
Leaves lanceolate or elliptic-lanceolate, margins serrulate; female flowers with tubular or campanulate perianth which becomes fleshy and persistent in
fruit ……………. 21
21. Leaves 3-veined to apex with a few lateral veins only at apex; inflorescence of panicles 4-7 cm long ………. 13. Sarcochlamys.
Leaves 3-veined only to middle, pinnately veined in upper half; inflorescence of cymes 0.5- 1.5 cm ………………. 15. Debregeasia (D.longijolia)
22. Flowers borne on old wood, clusters sessile or forming cymes; stigma sessile, brush-like; perianth persistent as a fleshy cup around base of achene …. 14. Oreocnide
Flowers borne amongst leaves, clusters sessile, axillary or aggregated into simple, leafless spikes, perianth dry, enclosing achene ………. 23
23. Style not jointed on to ovary, persistent in fruit ………………. 10. Boehmeria
Style jointed on to ovary, deciduous in fruit. …… 12. Pouzolzia (P. sanguinea)

PLANT TAXONOMY 2E By SHARMA (2011)- Details


 
 
 
 
 

Leave a Reply

Your email address will not be published. Required fields are marked *