Literatura basica

Agave arubensis Hummelinck nov. spec. 9).

Plants acaulescent, suckering (?). Rosette 130-160 cm diam., with rather few leaves. Leaves 5-6 times as long as broad, 65-80 cm by 13-14 cm, broadly lanceolate, usually slightly acuminate, widest somewhat below or in the middle, with rather slender neck, 6-y cm broad, slightly S-curved, usually round condupli-cate. Spines acicular, straight or very slightly upcurved at the top, sometimes slightly flexuous, usually rough, covered with very many minute tubercles, narrowly or broadly grooved below or to the middle, involute or nearly not involute towards the base, with margin blunt or rather sharp, smooth or with few small or very small prickles, shortly decurrent, dorsally rather slightly intruding or not intruding into the green tissue, 27-32 mm by 2 1/2-4 mm by 2 1/2-4 mm. Prickles usually pointing downwards somewhat below the middle of the leaf, often upcurved at the leaf top, 8-12 per 10 cm, 4-6 mm, exceptionally 7 mm in length, slender aciculate to a well or rather well developed base, on rather weakly to strongly developed green or hardening prominences, usually rough at the base. Inflorescence 350-500 cm high, rather poorly capsuliferous, freely bulbiferous. Panicle 2/3-1/2 total length, narrowly oblong, 4-5 times as long as broad, somewhat decurrent, with rather many, slightly S-curved, more or less ascending branches. Pedicels 4-7 mm. Peduncle 4-5 cm broad, with few bracts, the highest bract 7-11 cm, the lowest 11-17 cm long. Flowers with tube 7-8 mm. Segments 19-21 mm long. Filaments inserted 2-4 mm below the throat, 30-35 mm long. Anthers 14-19 mm. Style 35-40 mm, equaling the filaments. Capsules narrowly oblong, 2 1/2-2 2/3 times as long as broad if green, nearly 3 times as long as broad if dried, 33-40 mm by 12-15 mm, stipitated if green, long stipitated if dried, long beaked. Seeds 4 1/2-5 mm by 4-4 1/2 mm. Bulbils distributed over the whole panicle, especially in the lowest parts, in the top and in the axils of the highest bracts on the peduncle, downwards to or beyond the middle of the peduncle.

Aruba. 550 m S. of Fontein (type locality), 5. VII. 1930, on debris of coral rock, 30 m, soc. 2, deflor. (No 17a, fig. 14-15, 2 specim., pl. IVb; No 17b, pl. IVa, flowerrests and capsules).

a A. arubensis Humm. Aruba, near Fontein (No. 18).

5 Inflorescences were measured: average length 440 cm, max. 510 cm, min. 365 cm; av. length of panicle 270 cm, max. 335 cm, min. 210 cm; av. breadth of panicle 60 cm, max. 73 cm, min. 52 cm; av. length of largest branch 33 cm, max. 40 cm, min. 25 cm; av. number of branches exceeding 10 cm 28, max. 34, min. 24; av. diam. of peduncle 4 1/2 cm, max. 5 cm, min. 4 cm; av. number of bracts 9, max. 14, min. 7; av. length of highest bract 9 cm, max. 11 1/2 cm, min. 7 cm; av. length of lowest bract 13 1/2 cm, max. 17 1/2 cm, min. 10 cm.

The vegetative parts of these plants show no differences which would justify a separation of species or even of variety from the form of A. vivipara (not discussed here!) which grow in their immediate neighbourhood. But the generative parts show such a number of remarkable differences, per example the long tube with low inserted filaments, the form of capsules and the small number of bracts, that I consider this new species to be well defined.

Aruba, Droemidera, 1550 m S. of Kasioenti and 1750 m S. W. of Fontein, 5. VII. 1930, on debris of coral rock, ca 40 m, soc. 1-2, deflor. (No 18, pl. IIIa, sev. specim.).

a A. arubensis Humm. Aruba, (No. 17b, type), showing green and drying fruit with flowerrest, bulbil, seeds and part of whithered flower (nat. size).

These specimens agree well with the description given above, but: Leaves 4 1/3-4 1/2 times as long as broad, 60-70 cm by 15-16 cm. Spines 23-27 mm by 3-3 1/2 mm by 3-31/2 mm. — 2 Inflorescences were measured: total length 445-525 cm; length of panicle 300-425 cm; breadth of panicle 80-105 cm; length of largest branch 43-60 cm; number of branches exceeding 10 cm 28-35; diam. of peduncle 5-5 3/4 cm; number of bracts 4-7; length of highest bract 13-20 cm; length of lowest bract 16-24 cm.

9) A. arubensis Hummelinck, nov. spec.

Folia lanceolata, 5-6 partibus longiora quam lata, 65-80 cm longa, 13-14 cm lata. Spinae terminales aciculares, rectae, vel apice parum curvatae, internum subflexuosae, plerumque rugosae, basi vel ad medium anguste vel late sulcatae, basi involutae vel vix involutae, breviter decurrentes, dorso in textum viride paululum vel vix ingre-dientes, 27-32 mm longae, 2 1/2-4 mm diametro. Aculei marginales 8-12 in 10 cm, 4-7 mm longi, aciculati, basi dilatati. Inflorescentia 350-500 cm alta, bulbifera. Panicula 2/3-1/2 partem inflorescentiae metiens, anguste oblonga, pedicellis 4-7 mm longis. Pedunculus 7-14 bracteatus. Florum tubi 7-8 mm longi, segmentis 19-21 mm longis. Filamenta 2-4 mm sub fauce inserta, 30-35 mm longa, antheris 14-19 mm longis. Stylus 35-40 mm longus. Capsulae anguste oblongae, 2 1/2-3 partibus longiores quam latae, 35-40 mm longae, 12-15 mm latae, stipitatae, rostratae Semina 4 1/2-5 mm longa, 4-4 1/2 mm lata.

The species has been named after the island on which it occurs.

a A. arubensis Humm. Aruba, (No. 17a, type), showing leaftips and pieces of leafmargin (nat. size).

Agave arubensis Humm. nov. spec.

Leaves lanceolate, 4.3-6 times as long as broad, 60-80 cm in length. Spines acicular, grooved, involute or nearly not involute, slightly decurrent, slightly or not intruding, rough, 27-32 by 2.5-4 by 2.5 by 4 mm. Prickles 8-12 in 10 cm, 4-6 mm in length. Inflorescence 350-500 cm high; panicle 0.5-0.7 total length; pedicels 4-7 mm; bracts 3-14. Flowers with tube 7-8 mm; segments 19-21 mm; filaments inserted 2-4 mm below the throat, 30-35 mm in length; anthers 14-19 mm; style 35-40 mm. Capsules 2.3-3 times as long as broad, 33-40 by 12-15 mm, distinctly stipitate, distinctly beaked. Seeds 4.5-5 by 4-4.5 mm. - Aruba, on coral rock.